U.S. patent application number 15/637636 was filed with the patent office on 2017-10-26 for precoding matrix indicator pmi feedback method.
The applicant listed for this patent is Huawei Technologies Co., Ltd.. Invention is credited to Jianghua Liu, Jianqin Liu, Kunpeng Liu, Qiang Wu, Leiming Zhang.
Application Number | 20170310372 15/637636 |
Document ID | / |
Family ID | 56283970 |
Filed Date | 2017-10-26 |
United States Patent
Application |
20170310372 |
Kind Code |
A1 |
Wu; Qiang ; et al. |
October 26, 2017 |
PRECODING MATRIX INDICATOR PMI FEEDBACK METHOD
Abstract
In a 3D MIMO scenario with 16 antenna ports, antenna ports can
be extended in different directions because of different
configuration manners of the antenna ports. An apparatus and method
where different antenna port counting manners are determined in
different configurations are provided, so that in different
configurations, a matrix whose dimension is 8 and a matrix whose
dimension is 2 are determined in a precoding codebook, and a value
of a PMI is fed back to indicate a precoding matrix.
Inventors: |
Wu; Qiang; (Beijing, CN)
; Zhang; Leiming; (Beijing, CN) ; Liu;
Jianqin; (Beijing, CN) ; Liu; Kunpeng;
(Beijing, CN) ; Liu; Jianghua; (Beijing,
CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Huawei Technologies Co., Ltd. |
Shenzhen |
|
CN |
|
|
Family ID: |
56283970 |
Appl. No.: |
15/637636 |
Filed: |
June 29, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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PCT/CN2014/095931 |
Dec 31, 2014 |
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15637636 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04L 5/0048 20130101;
H04W 72/0413 20130101; H04W 88/08 20130101; H04B 7/0456 20130101;
H04B 7/0417 20130101 |
International
Class: |
H04B 7/0417 20060101
H04B007/0417; H04B 7/0456 20060101 H04B007/0456; H04W 72/04
20090101 H04W072/04 |
Claims
1. A precoding matrix indicator (PMI) feedback method, comprising:
receiving, by user equipment (UE), a reference signal; determining,
by the UE, that a quantity of antenna ports used by a base station
to transmit the reference signal is 16; determining, by the UE, a
precoding matrix from a precoding matrix set corresponding to the
16 antenna ports, wherein each precoding matrix W in the precoding
matrix set satisfies the following relationship: W=W.sub.1W.sub.2
or W=W.sub.2W.sub.1, wherein W.sub.1 is a first precoding
submatrix, W.sub.2 is a second precoding submatrix, indicates a
Kronecker product, and a row quantity of the first precoding
submatrix is 2 and a row quantity of the second precoding submatrix
is 8, or a column quantity of the first precoding submatrix is 8
and a column quantity of the second precoding submatrix is 2; and
sending, by the UE, a precoding matrix indicator (PMI)
corresponding to the precoding matrix to the base station.
2. The method according to claim 1, wherein determining, by the UE,
the precoding matrix from the precoding matrix set comprises:
determining, by the UE, the first precoding submatrix and the
second precoding submatrix from the precoding matrix set; and
determining, by the UE, the precoding matrix according to the first
precoding submatrix and the second precoding submatrix.
3. The method according to claim 1, wherein: the first precoding
submatrix is a precoding submatrix in a first direction, and the
second precoding submatrix is a precoding submatrix in a second
direction; or the first precoding submatrix is a precoding
submatrix in a second direction and the second precoding submatrix
is a precoding submatrix in a first direction.
4. The method according to claim 1, further comprising:
determining, by the UE, a bit quantity corresponding to a PMI of
W.sub.1 and a bit quantity corresponding to a PMI of W.sub.2;
determining, by the UE, the PMI of W.sub.1 and the PMI of W.sub.2
according to the bit quantity corresponding to the PMI of W.sub.1
and the bit quantity corresponding to the PMI of W.sub.2; and
sending, by the UE, the precoding matrix indicator (PMI)
corresponding to the precoding matrix to the base station
comprises: sending the PMI of W.sub.1 and the PMI of W.sub.2 to the
base station.
5. The method according to claim 4, wherein determining, by the UE,
the bit quantity corresponding to the PMI of W.sub.1 and the bit
quantity corresponding to the PMI of W.sub.2 comprises: receiving,
by the UE, bit indication information sent by the base station,
wherein the bit indication information is used to indicate at least
one of the bit quantity corresponding to the PMI of W.sub.1 or the
bit quantity corresponding to the PMI of W.sub.2.
6. A precoding matrix indicator (PMI) feedback method, comprising:
sending, by a base station, a reference signal to a user equipment
(UE) by using 16 antenna ports; receiving, by the base station, a
precoding matrix indicator (PMI) fed back by the UE; determining,
by the base station, a precoding matrix corresponding to the PMI
from a precoding matrix set corresponding to the 16 antenna ports,
wherein each precoding matrix W in the precoding matrix set
satisfies the following relationship: W=W.sub.1W.sub.2 or
W=W.sub.2W.sub.1, wherein W.sub.1 is a first precoding submatrix,
W.sub.2 wherein a first precoding submatrix, indicates a Kronecker
product, and a row quantity of the first precoding submatrix is 2
and a row quantity of the second precoding submatrix is 8, or a
column quantity of the first precoding submatrix is 8 and a column
quantity of the second precoding submatrix is 2; and sending, by
the base station, data to the UE by using the precoding matrix.
7. The method according to claim 6, wherein: a quantity of PMIs is
at least two; and determining, by the base station, the precoding
matrix from the precoding matrix set corresponding to the 16
antenna ports comprises: determining, by the base station, the
first precoding submatrix and the second precoding submatrix
according to a PMI of the first precoding submatrix and a PMI of
the second precoding submatrix; and determining, by the base
station, the precoding matrix according to the first precoding
submatrix and the second precoding submatrix.
8. The method according to claim 6, wherein: the first precoding
submatrix is a precoding submatrix in a first direction, and the
second precoding submatrix is a precoding submatrix in a second
direction; or the first precoding submatrix is a precoding
submatrix in a second direction and the second precoding submatrix
is a precoding submatrix in a first direction.
9. The method according to claim 6, further comprising:
determining, by the base station, a bit quantity corresponding to
the PMI of W.sub.1 and a bit quantity corresponding to the PMI of
W.sub.2; and receiving, by the base station according to the bit
quantity of the PMI corresponding to W.sub.1 and the bit quantity
of the PMI corresponding to W.sub.2, the PMI of W.sub.1 and the PMI
of W.sub.2 that are fed back by the UE.
10. The method according to claim 9, further comprising: sending,
by the base station, bit indication information to the UE, wherein
the bit indication information is used to indicate at least one of
the bit quantity corresponding to the PMI of W.sub.1 or the bit
quantity corresponding to the PMI of W.sub.2.
11. User equipment (UE), comprising: a receiving unit, configured
to receive a reference signal; a determining unit, configured to:
determine that a quantity of antenna ports used by a base station
to transmit the reference signal is 16; and determine a precoding
matrix from a precoding matrix set corresponding to the 16 antenna
ports; wherein the reference signal is received by the receiving
unit, and each precoding matrix W in the precoding matrix set
satisfies the following relationship: W=W.sub.1W.sub.2 or
W=W.sub.2W.sub.1, wherein W.sub.1 is a first precoding submatrix,
W.sub.2 is a second precoding submatrix, indicates a Kronecker
product, and a row quantity of the first precoding submatrix is 2
and a row quantity of the second precoding submatrix is 8, or a
column quantity of the first precoding submatrix is 8 and a column
quantity of the second precoding submatrix is 2; and a sending
unit, configured to send a precoding matrix indicator (PMI)
corresponding to the precoding matrix to the base station, wherein
the precoding matrix is determined by the determining unit.
12. The UE according to claim 11, wherein the determining unit is
further configured to: determine the first precoding submatrix and
the second precoding submatrix from the precoding matrix set; and
determine the precoding matrix according to the first precoding
submatrix and the second precoding submatrix.
13. The UE according to claim 11, wherein: the first precoding
submatrix is a precoding submatrix in a first direction, and the
second precoding submatrix is a precoding submatrix in a second
direction; or the first precoding submatrix is a precoding
submatrix in a second direction and the second precoding submatrix
is a precoding submatrix in a first direction.
14. The UE according to claim 11, wherein the determining unit is
further configured to: determine a bit quantity corresponding to a
PMI of W.sub.1 and a bit quantity corresponding to a PMI of
W.sub.2; and determine the PMI of W.sub.1 and the PMI of W.sub.2
according to the bit quantity corresponding to the PMI of W.sub.1
and the bit quantity corresponding to the PMI of W.sub.2.
15. The UE according to claim 14, wherein the determining unit is
further configured to control the receiving unit to receive bit
indication information sent by the base station, wherein the bit
indication information is used to indicate at least one of the bit
quantity corresponding to the PMI of W.sub.1 or the bit quantity
corresponding to the PMI of W.sub.2.
16. A base station, comprising: a sending unit, configured to send
a reference signal to a user equipment (UE) by using 16 antenna
ports; a receiving unit, configured to receive a precoding matrix
indicator (PMI) fed back by the UE, wherein the PMI is determined
according to the reference signal sent by the sending unit; and a
determining unit, configured to determine a precoding matrix
corresponding to the PMI received by the receiving unit from a
precoding matrix set corresponding to the 16 antenna ports, wherein
each precoding matrix W in the precoding matrix set satisfies the
following relationship: W=W.sub.1W.sub.2 or W=W.sub.2W.sub.1,
wherein W.sub.1 is a first precoding submatrix, W.sub.2 is a second
precoding submatrix, indicates a Kronecker product, and a row
quantity of the first precoding submatrix is 2 and a row quantity
of the second precoding submatrix is 8, or a column quantity of the
first precoding submatrix is 8 and a column quantity of the second
precoding submatrix is 2; wherein the sending unit is further
configured to send data to the UE by using the precoding matrix
determined by the determining unit.
17. The base station according to claim 16, wherein: a quantity of
PMIs is at least two; and the determining unit is further
configured to: determine the first precoding submatrix and the
second precoding submatrix according to a PMI of the first
precoding submatrix and a PMI of the second precoding submatrix;
and determine the precoding matrix according to the first precoding
submatrix and the second precoding submatrix.
18. The base station according to claim 16, wherein: the first
precoding submatrix is a precoding submatrix in a first direction,
and the second precoding submatrix is a precoding submatrix in a
second direction; or the first precoding submatrix is a precoding
submatrix in a second direction and the second precoding submatrix
is a precoding submatrix in a first direction.
19. The base station according to claim 16, wherein: the
determining unit is further configured to determine a bit quantity
of a PMI of W.sub.1 and a bit quantity of a PMI corresponding to
W.sub.2; and the receiving unit is further configured to receive,
according to the bit quantity of the PMI corresponding to W.sub.1
and the bit quantity of the PMI corresponding to W.sub.2, the PMI
of W.sub.1 and the PMI of W.sub.2 that are fed back by the UE.
20. The base station according to claim 19, wherein the determining
unit is further configured to control the sending unit to send bit
indication information to the UE, wherein the bit indication
information is used to indicate at least one of the bit quantity
corresponding to the PMI of W.sub.1 or the bit quantity
corresponding to the PMI of W.sub.2.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of International
Application No. PCT/CN2014/095931, filed on Dec. 31, 2014, the
disclosure of which is hereby incorporated by reference in its
entirety.
TECHNICAL FIELD
[0002] The present disclosure relates to the field of wireless
communications technologies, and in particular, to a precoding
matrix indicator feedback method, user equipment, and base
station.
BACKGROUND
[0003] A long term evolution (LTE) technology is long term
evolution of a universal mobile telecommunications system (UMTS)
technology standard formulated by the 3rd generation partnership
project (3GPP) organization. Key transmission technologies such as
multiple-input multiple-output (MIMO) are introduced into an LTE
system. Therefore, spectral efficiency and a data transmission rate
are significantly increased. By means of a transmit precoding
technology and a receive signal combination technology, a
MIMO-based wireless communications system can obtain diversity and
array gains. The MIMO-based wireless communications system needs to
perform precoding processing on a signal. A signal transmission
function based on precoding may be expressed as:
y=H{circumflex over (V)}s+n,
[0004] where y represents a received signal vector, H represents a
channel matrix, {circumflex over (V)} represents a precoding
matrix, s represents a transmitted signal vector, and n represents
a measurement noise. The transmitted signal vectors on a transmit
end passes through the precoding matrix {circumflex over (V)} for
precoding, and a precoded matrix is obtained. The precoded matrix
passes through the channel matrix H, the measurement noise n is
added to the precoded matrix, and then the received signal vector y
is received on a receive end.
[0005] To implement optimal precoding, a transmitter usually needs
to obtain channel state information (CSI) in advance. The
transmitter and a receiver may be respectively a base station
device or a terminal device. In a downlink data transmission
process, the transmitter may be a base station device, and the
receiver may be a terminal device. A commonly used method is that
the terminal device quantizes instantaneous CSI and reports the CSI
to the base station.
[0006] The CSI information reported by the terminal includes rank
indicator (RI) information, precoding matrix indicator (PMI)
information, channel quality indicator (CQI) information, and the
like. An RI may be used to indicate a transport layer quantity and
a precoding matrix {circumflex over (V)} that are used for data
transmission. A PMI may be used to indicate the precoding matrix
{circumflex over (V)} used for data transmission. Herein, a
precoding matrix V may be determined first by using the PMI, and
then {circumflex over (V)} is indicated according to the RI or a
determined rule.
[0007] In some 3D MIMO (3 Dimension MIMO) scenarios, on one
carrier, PMIs of two precoding matrices need to be fed back, to
respectively indicate a precoding matrix in a vertical direction
and a precoding matrix in a horizontal direction. A precoding
matrix may be indicated by using a Kronecker product of a precoding
matrix in a vertical direction and a precoding matrix in a
horizontal direction. A precoding matrix V.sub.1 may be expressed
as follows:
V.sub.1=AB,
[0008] where indicates a Kronecker product. A size of the matrix
V.sub.1 is determined by row and column quantities of a precoding
matrix A in the vertical direction and row and column quantities of
a precoding matrix B in the horizontal direction. Herein, A may
also represent a precoding matrix in the horizontal direction, and
correspondingly, B represents a precoding matrix in the vertical
direction.
[0009] Usually, dimensions of A and B are determined by an antenna
port quantity. In a process of selecting a codebook, a precoding
matrix set needs to be further determined according to a
distribution status of antenna ports. User equipment and a base
station determine different codebook sets for different antenna
port configuration manners. The UE or the base station needs to
store the different codebook sets, causing waste of storage
resources.
SUMMARY
[0010] Embodiments of the present disclosure provide a precoding
matrix indicator feedback method, user equipment and a base
station, so as to resolve a problem that different codebooks need
to be determined for different antenna port configurations, and
reduce storage resources.
[0011] According to a first aspect, an embodiment of the present
disclosure provides a precoding matrix indicator (PMI) feedback
method, including: receiving, by user equipment (UE), a reference
signal; determining, by the UE, that a quantity of antenna ports
used by a base station to transmit the reference signal is 16;
determining, by the UE, a precoding matrix from a precoding matrix
set corresponding to the 16 antenna ports, where each precoding
matrix W in the precoding matrix set satisfies the following
relationship: W=W.sub.1W.sub.2 or W=W.sub.2W.sub.1, where W.sub.1
is a first precoding submatrix, W.sub.2 is a second precoding
submatrix, indicates a Kronecker product, and a row quantity of the
first precoding submatrix is 2 and a row quantity of the second
precoding submatrix is 8, or a column quantity of the first
precoding submatrix is 8 and a column quantity of the second
precoding submatrix is 2; and sending, by the UE, a precoding
matrix indicator (PMI) corresponding to the precoding matrix to the
base station.
[0012] In a first possible implementation manner of the first
aspect, the determining, by the UE, a precoding matrix from a
precoding matrix set includes: determining, by the UE, the first
precoding submatrix and the second precoding submatrix from the
precoding matrix set; and determining, by the UE, the precoding
matrix according to the first precoding submatrix and the second
precoding submatrix.
[0013] With reference to the first aspect or the first possible
implementation manner of the first aspect, in a second possible
implementation manner, the first precoding submatrix is a precoding
submatrix in a first direction, and the second precoding submatrix
is a precoding submatrix in a second direction, or the first
precoding submatrix is a precoding submatrix in a second direction
and the second precoding submatrix is a precoding submatrix in a
first direction.
[0014] With reference to the second possible implementation manner
of the first aspect, in a third possible implementation manner, a
configuration manner of the 16 antenna ports includes any one of
the following:
[0015] two antenna ports are configured in the first direction and
eight antenna ports are configured in the second direction;
[0016] four antenna ports are configured in the first direction and
four antenna ports are configured in the second direction;
[0017] eight antenna ports are configured in the first direction
and two antenna ports are configured in the second direction;
or
[0018] 16 antenna ports are configured in the first direction and
one antenna port is configured in the second direction.
[0019] With reference to the third possible implementation manner
of the first aspect, in a fourth possible implementation manner, a
precoding matrix in the first direction is a precoding matrix in a
horizontal direction, and a precoding matrix in the second
direction is a precoding matrix in a vertical direction, or a
precoding matrix in the first direction is a precoding matrix in a
vertical direction, and a precoding matrix in the second direction
is a precoding matrix in a horizontal direction.
[0020] With reference to any one of the first aspect or the first
to the fourth possible implementation manners of the first aspect,
in a fifth possible implementation manner, the first precoding
submatrix is a product of a third precoding submatrix and a fourth
precoding submatrix; and/or the second precoding submatrix is a
product of a fifth precoding submatrix and a sixth precoding
submatrix.
[0021] With reference to any one of the first aspect or the first
to the fifth possible implementation manners of the first aspect,
in a sixth possible implementation manner, the method includes:
determining, by the UE, a bit quantity corresponding to a PMI of
W.sub.1 and a bit quantity corresponding to a PMI of W.sub.2; and
determining, by the UE, the PMI of W.sub.1 and the PMI of W.sub.2
according to the bit quantity corresponding to the PMI of W.sub.1
and the bit quantity corresponding to the PMI of W.sub.2; and the
sending, by the UE, a precoding matrix indicator (PMI)
corresponding to the precoding matrix to the base station includes:
sending the PMI of W.sub.1 and the PMI of W.sub.2 to the base
station.
[0022] With reference to the sixth possible implementation manner
of the first aspect, in a seventh possible implementation manner,
the determining, by the UE, a bit quantity corresponding to a PMI
of W.sub.1 and a bit quantity corresponding to a PMI of W.sub.2
includes:
[0023] receiving, by the UE, bit indication information sent by the
base station, where the bit indication information is used to
indicate at least one of the bit quantity corresponding to the PMI
of W.sub.1 or the bit quantity corresponding to the PMI of
W.sub.2.
[0024] According to a second aspect, an embodiment of the present
disclosure provides a precoding matrix indicator (PMI) feedback
method, including: sending, by a base station, a reference signal
to UE by using 16 antenna ports; receiving, by the base station, a
precoding matrix indicator (PMI) fed back by the UE; determining,
by the base station, a precoding matrix corresponding to the PMI
from a precoding matrix set corresponding to the 16 antenna ports,
where each precoding matrix W in the precoding matrix set satisfies
the following relationship: W=W.sub.1W.sub.2 or W=W.sub.2W.sub.1,
where W.sub.1 is a first precoding submatrix, W.sub.2 is a second
precoding submatrix, indicates a Kronecker product, and a row
quantity of the first precoding submatrix is 2 and a row quantity
of the second precoding submatrix is 8, or a column quantity of the
first precoding submatrix is 8 and a column quantity of the second
precoding submatrix is 2; and sending, by the base station, data to
the UE by using the precoding matrix.
[0025] In a first possible implementation manner of the second
aspect, a quantity of PMIs is at least two; and the determining, by
the base station, a precoding matrix from a precoding matrix set
corresponding to the 16 antenna ports includes: determining, by the
base station, the first precoding submatrix and the second
precoding submatrix according to a PMI of the first precoding
submatrix and a PMI of the second precoding submatrix; and
determining, by the base station, the precoding matrix according to
the first precoding submatrix and the second precoding
submatrix.
[0026] With reference to the second aspect or the first possible
implementation manner of the second aspect, in a second possible
implementation manner, the first precoding submatrix is a precoding
submatrix in a first direction, and the second precoding submatrix
is a precoding submatrix in a second direction, or the first
precoding submatrix is a precoding submatrix in a second direction
and the second precoding submatrix is a precoding submatrix in a
first direction.
[0027] With reference to the second possible implementation manner
of the second aspect, in a third possible implementation manner, a
configuration manner of the 16 antenna ports includes any one of
the following:
[0028] two antenna ports are configured in the first direction and
eight antenna ports are configured in the second direction;
[0029] four antenna ports are configured in the first direction and
four antenna ports are configured in the second direction;
[0030] eight antenna ports are configured in the first direction
and two antenna ports are configured in the second direction;
or
[0031] 16 antenna ports are configured in the first direction and
one antenna port is configured in the second direction.
[0032] With reference to the third possible implementation manner
of the second aspect, in a fourth possible implementation manner, a
precoding matrix in the first direction is a precoding matrix in a
horizontal direction, and a precoding matrix in the second
direction is a precoding matrix in a vertical direction, or a
precoding matrix in the first direction is a precoding matrix in a
vertical direction, and a precoding matrix in the second direction
is a precoding matrix in a horizontal direction.
[0033] With reference to any one of the second aspect or the first
to the fourth possible implementation manners of the second aspect,
in a fifth possible implementation manner, the first precoding
submatrix is a product of a third precoding submatrix and a fourth
precoding submatrix; and/or the second precoding submatrix is a
product of a fifth precoding submatrix and a sixth precoding
submatrix.
[0034] With reference to any one of the second aspect or the first
to the fifth possible implementation manners of the second aspect,
in a sixth possible implementation manner, the method includes:
determining, by the base station, a bit quantity corresponding to
the PMI of W.sub.1 and a bit quantity corresponding to the PMI of
W.sub.2; and receiving, by the base station according to the bit
quantity of the PMI corresponding to W.sub.1 and the bit quantity
of the PMI corresponding to W.sub.2, the PMI of W.sub.1 and the PMI
of W.sub.2 that are fed back by the UE.
[0035] With reference to the sixth possible implementation manner
of the second aspect, in a seventh possible implementation manner,
the method further includes:
[0036] sending, by the base station, bit indication information to
the UE, where the bit indication information is used to indicate at
least one of the bit quantity corresponding to the PMI of W.sub.1
or the bit quantity corresponding to the PMI of W.sub.2.
[0037] According to a third aspect, an embodiment of the present
disclosure provides user equipment (UE), including: a receiving
unit, configured to receive a reference signal; a determining unit,
configured to: determine that a quantity of antenna ports used by a
base station to transmit the reference signal is 16, and determine
a precoding matrix from a precoding matrix set corresponding to the
16 antenna ports, where the reference signal is received by the
receiving unit, and each precoding matrix W in the precoding matrix
set satisfies the following relationship: W=W.sub.1W.sub.2 or
W=W.sub.2W.sub.1, where W.sub.1 is a first precoding submatrix,
W.sub.2 is a second precoding submatrix, indicates a Kronecker
product, and a row quantity of the first precoding submatrix is 2
and a row quantity of the second precoding submatrix is 8, or a
column quantity of the first precoding submatrix is 8 and a column
quantity of the second precoding submatrix is 2; and a sending
unit, configured to send a precoding matrix indicator (PMI)
corresponding to the precoding matrix to the base station, where
the precoding matrix is determined by the determining unit.
[0038] In a first possible implementation manner of the third
aspect, the determining unit being configured to determine a
precoding matrix from a precoding matrix set includes: determining
the first precoding submatrix and the second precoding submatrix
from the precoding matrix set; and determining the precoding matrix
according to the first precoding submatrix and the second precoding
submatrix.
[0039] With reference to the third aspect or the first possible
implementation manner of the third aspect, in a second possible
implementation manner, the first precoding submatrix is a precoding
submatrix in a first direction, and the second precoding submatrix
is a precoding submatrix in a second direction, or the first
precoding submatrix is a precoding submatrix in a second direction
and the second precoding submatrix is a precoding submatrix in a
first direction.
[0040] With reference to the second possible implementation manner
of the third aspect, in a third possible implementation manner, a
configuration manner of the 16 antenna ports includes any one of
the following:
[0041] two antenna ports are configured in the first direction and
eight antenna ports are configured in the second direction;
[0042] four antenna ports are configured in the first direction and
four antenna ports are configured in the second direction;
[0043] eight antenna ports are configured in the first direction
and two antenna ports are configured in the second direction;
or
[0044] 16 antenna ports are configured in the first direction and
one antenna port is configured in the second direction.
[0045] With reference to the third possible implementation manner
of the third aspect, in a fourth possible implementation manner, a
precoding matrix in the first direction is a precoding matrix in a
horizontal direction, and a precoding matrix in the second
direction is a precoding matrix in a vertical direction, or a
precoding matrix in the first direction is a precoding matrix in a
vertical direction, and a precoding matrix in the second direction
is a precoding matrix in a horizontal direction.
[0046] With reference to any one of the third aspect or the first
to the fourth possible implementation manners of the third aspect,
in a fifth possible implementation manner, the first precoding
submatrix is a product of a third precoding submatrix and a fourth
precoding submatrix; and/or the second precoding submatrix is a
product of a fifth precoding submatrix and a sixth precoding
submatrix.
[0047] With reference to any one of the third aspect or the first
to the fifth possible implementation manners of the third aspect,
in a sixth possible implementation manner, the determining unit is
further configured to: determine a bit quantity corresponding to a
PMI of W.sub.1 and a bit quantity corresponding to a PMI of
W.sub.2, and determine the PMI of W.sub.1 and the PMI of W.sub.2
according to the bit quantity corresponding to the PMI of W.sub.1
and the bit quantity corresponding to the PMI of W.sub.2.
[0048] With reference to the sixth possible implementation manner
of the third aspect, in a seventh possible implementation manner,
the determining unit is further configured to control the receiving
unit to receive bit indication information sent by the base
station, where the bit indication information is used to indicate
at least one of the bit quantity corresponding to the PMI of
W.sub.1 or the bit quantity corresponding to the PMI of
W.sub.2.
[0049] According to a fourth aspect, an embodiment of the present
disclosure provides a base station, including:
[0050] a sending unit, configured to send a reference signal to UE
by using 16 antenna ports;
[0051] a receiving unit, configured to receive a precoding matrix
indicator (PMI) fed back by the UE, where the PMI is determined
according to the reference signal sent by the sending unit; and
[0052] a determining unit, configured to determine a precoding
matrix corresponding to the PMI received by the receiving unit from
a precoding matrix set corresponding to the 16 antenna ports, where
each precoding matrix W in the precoding matrix set satisfies the
following relationship: W=W.sub.1W.sub.2 or W=W.sub.2W.sub.1, where
W.sub.1 is a first precoding submatrix, W.sub.2 is a second
precoding submatrix, indicates a Kronecker product, and a row
quantity of the first precoding submatrix is 2 and a row quantity
of the second precoding submatrix is 8, or a column quantity of the
first precoding submatrix is 8 and a column quantity of the second
precoding submatrix is 2, where
[0053] the sending unit is further configured to send data to the
UE by using the precoding matrix determined by the determining
unit.
[0054] In a first possible implementation manner of the fourth
aspect, a quantity of PMIs is at least two; and the determining
unit being configured to determine a precoding matrix from a
precoding matrix set corresponding to the 16 antenna ports
includes:
[0055] determining the first precoding submatrix and the second
precoding submatrix according to a PMI of the first precoding
submatrix and a PMI of the second precoding submatrix; and
determining the precoding matrix according to the first precoding
submatrix and the second precoding submatrix.
[0056] With reference to the fourth aspect or the first possible
implementation manner of the fourth aspect, in a second possible
implementation manner, the first precoding submatrix is a precoding
submatrix in a first direction, and the second precoding submatrix
is a precoding submatrix in a second direction, or the first
precoding submatrix is a precoding submatrix in a second direction
and the second precoding submatrix is a precoding submatrix in a
first direction.
[0057] With reference to the second possible implementation manner
of the fourth aspect, in a third possible implementation manner, a
configuration manner of the 16 antenna ports includes any one of
the following: two antenna ports are configured in the first
direction and eight antenna ports are configured in the second
direction; four antenna ports are configured in the first direction
and four antenna ports are configured in the second direction;
or
[0058] eight antenna ports are configured in the first direction
and two antenna ports are configured in the second direction; or 16
antenna ports are configured in the first direction and one antenna
port is configured in the second direction.
[0059] With reference to the third possible implementation manner
of the fourth aspect, in a fourth possible implementation manner, a
precoding matrix in the first direction is a precoding matrix in a
horizontal direction, and a precoding matrix in the second
direction is a precoding matrix in a vertical direction, or a
precoding matrix in the first direction is a precoding matrix in a
vertical direction, and a precoding matrix in the second direction
is a precoding matrix in a horizontal direction.
[0060] With reference to any one of the fourth aspect or the first
to the fourth possible implementation manners of the fourth aspect,
in a fifth possible implementation manner, the first precoding
submatrix is a product of a third precoding submatrix and a fourth
precoding submatrix; and/or
[0061] the second precoding submatrix is a product of a fifth
precoding submatrix and a sixth precoding submatrix.
[0062] With reference to any one of the fourth aspect or the first
to the fifth possible implementation manners of the fourth aspect,
in a sixth possible implementation manner, the determining unit is
further configured to determine a bit quantity of a PMI of W.sub.1
and a bit quantity of a PMI corresponding to W.sub.2; and the
receiving unit is further configured to receive, according to the
bit quantity of the PMI corresponding to W.sub.1 and the bit
quantity of the PMI corresponding to W.sub.2, the PMI of W.sub.1
and the PMI of W.sub.2 that are fed back by the UE.
[0063] With reference to the sixth possible implementation manner
of the fourth aspect, in a seventh possible implementation manner,
the determining unit is further configured to control the sending
unit to send bit indication information to the UE, where the bit
indication information is used to indicate at least one of the bit
quantity corresponding to the PMI of W.sub.1 or the bit quantity
corresponding to the PMI of W.sub.2.
[0064] By means of the foregoing solutions, in the embodiments of
the present disclosure, if it is determined that a total quantity
of antenna ports is fixed to 16, codebooks used in different
antenna port configurations are changed, so as to achieve an effect
of reducing storage resources and avoiding configuring multiple
codebooks by adding signaling.
BRIEF DESCRIPTION OF THE DRAWINGS
[0065] To describe the technical solutions in the embodiments of
the present disclosure more clearly, the following briefly
describes the accompanying drawings required for describing the
embodiments. Apparently, the accompanying drawings in the following
description show some embodiments of the present disclosure, and a
person of ordinary skill in the art may still derive other drawings
from these accompanying drawings without creative efforts.
[0066] FIG. 1 is a flowchart of a PMI feedback method on a UE side
according an embodiment of the present disclosure;
[0067] FIG. 2 is a flowchart of a PMI feedback method on a UE side
according an embodiment of the present disclosure;
[0068] FIG. 2a is a structural diagram of an antenna port
configuration according an embodiment of the present
disclosure;
[0069] FIG. 2b is a structural diagram of an antenna port
configuration according an embodiment of the present
disclosure;
[0070] FIG. 2c is a structural diagram of an antenna port
configuration according an embodiment of the present
disclosure;
[0071] FIG. 2d is a structural diagram of an antenna port
configuration according an embodiment of the present
disclosure;
[0072] FIG. 3 is a flowchart of a PMI feedback method on a UE side
according an embodiment of the present disclosure;
[0073] FIG. 4 is a flowchart of a PMI feedback method on a base
station side according an embodiment of the present disclosure;
[0074] FIG. 5 is a flowchart of a PMI feedback method on a base
station side according an embodiment of the present disclosure;
[0075] FIG. 6 is a flowchart of a PMI feedback method on a base
station side according an embodiment of the present disclosure;
[0076] FIG. 7 is a schematic diagram of a UE apparatus for
implementing PMI feedback according to an embodiment of the present
disclosure;
[0077] FIG. 8 is a schematic diagram of a UE apparatus for
implementing PMI feedback according to an embodiment of the present
disclosure;
[0078] FIG. 9 is a schematic diagram of a UE apparatus for
implementing PMI feedback according to an embodiment of the present
disclosure;
[0079] FIG. 10 is a schematic diagram of a base station for
implementing PMI feedback according to an embodiment of the present
disclosure;
[0080] FIG. 11 is a schematic diagram of a base station for
implementing PMI feedback according to an embodiment of the present
disclosure;
[0081] FIG. 12 is a schematic diagram of a base station for
implementing PMI feedback according to an embodiment of the present
disclosure;
[0082] FIG. 13 is a flowchart of a PMI feedback method for
implementing interaction between a base station side and a UE side
according an embodiment of the present disclosure; and
[0083] FIG. 14 is a flowchart of a PMI feedback method for
implementing interaction between a base station side and a UE side
according an embodiment of the present disclosure.
DETAILED DESCRIPTION
[0084] Usually, dimensions of A and B are determined by an antenna
port quantity. In a process of selecting a codebook, a precoding
matrix set needs to be further determined according to a
distribution status of antenna ports. User equipment and a network
device determine different codebook sets for different antenna port
configuration manners. The UE or a base station needs to store
various types of codebooks, causing waste of storage resources. On
the other hand, if storage resources are fixed, when all the
foregoing five codebooks are stored, the UE needs to configure,
according to a case of insufficient measurement accuracy, for
example, in a scenario of 16 antennas, a codebook set having five
dimensions: 1, 2, 4, 8, and 16. In this case, the base station
and/or the UE needs to store four types of codebooks. If accuracy
is ensured, the UE or the base station needs to store various types
of codebooks, causing waste of storage resources. On the other
hand, if storage resources are fixed, when all the foregoing five
codebooks are stored, measurement accuracy of the UE is
insufficient.
[0085] The following clearly describes the technical solutions in
the embodiments of the present disclosure with reference to the
accompanying drawings in the embodiments of the present disclosure.
Apparently, the described embodiments are a part rather than all of
the embodiments of the present disclosure. All other embodiments
obtained by a person of ordinary skill in the art based on the
embodiments of the present disclosure without creative efforts
shall fall within the protection scope of the present
disclosure.
[0086] It should be understood that, the base station involved in
the present disclosure may be, but is not limited to, a NodeB, a
base station (BS), an access point, a transmission point (TP), an
evolved NodeB (eNB), or a relay. The user equipment (UE) involved
in the present disclosure may be, but is not limited to, a mobile
station (MS), a relay, a mobile telephone, a handset, portable
equipment, or a mobile or non-mobile terminal.
[0087] FIG. 1 is a schematic flowchart of a communication method
according to an embodiment of the present disclosure, and relates
to a precoding matrix indicator (PMI) feedback method. The method
specifically includes the following steps.
[0088] Step 101. User equipment (UE) receives a reference
signal.
[0089] Step 102. The UE determines that a quantity of antenna ports
used by a base station to transmit the reference signal is 16.
[0090] Step 103. The UE determines a precoding matrix from a
precoding matrix set corresponding to the 16 antenna ports, where
each precoding matrix W in the precoding matrix set satisfies the
following relationship: W=W.sub.1W.sub.2 or W=W.sub.2W.sub.1, where
W.sub.1 is a first precoding submatrix, W.sub.2 is a second
precoding submatrix, indicates a Kronecker product, and a row
quantity of the first precoding submatrix is 2 and a row quantity
of the second precoding submatrix is 8, or a column quantity of the
first precoding submatrix is 8 and a column quantity of the second
precoding submatrix is 2.
[0091] For ease of description and illustration, the satisfied
relationship: W=W.sub.1W.sub.2 or W=W.sub.2W.sub.1, is collectively
referred to as a first relationship in this embodiment of the
present disclosure.
[0092] Step 104. The UE sends a precoding matrix indicator (PMI)
corresponding to the precoding matrix to the base station.
[0093] According to the embodiments shown in FIG. 1, in a
configuration of 16 antenna ports, after performing measurement
according to a reference signal to obtain a measurement result,
user equipment determines, from only one codebook set, a first
precoding matrix whose corresponding dimension is 2 and a second
precoding matrix whose dimension is 8, thereby reducing storage
resources and air interface configuration resources.
[0094] FIG. 2 is a schematic flowchart of a communication method
according to an embodiment of the present disclosure, and relates
to a precoding matrix indicator (PMI) feedback method. The method
specifically includes the following steps.
[0095] Step 201. User equipment (UE) receives a reference
signal.
[0096] Step 202. The UE determines that a quantity of antenna ports
used by a base station to transmit the reference signal is 16.
[0097] It should be understood that, the present disclosure does
not limit a specific method for determining, by the UE, that a
quantity of antenna ports used by the base station to transmit the
reference signal is 16. The method may be preconfigured by the UE,
or may be determined by means of measurement. In an embodiment, the
UE may determine the quantity of antenna ports according to the
reference signal. Such a determining process may be an implicit
determining method. For example, if the UE receives only 16
reference signals, the UE can determine that the quantity of
antenna ports used by the base station to transmit the reference
signal is 16. In another embodiment, the quantity of antenna ports
used by the base station to transmit the reference signal may not
be determined by the UE by using the reference signal, but is
configured by using some signaling, or has been prestored in the UE
by means of presetting or in another manner. In addition, in this
case, step 202 may be performed before step 201 or step 202 and
step 201 may be performed at the same time.
[0098] Step 203. The UE determines a precoding matrix from a
precoding matrix set corresponding to the 16 antenna ports, where
each precoding matrix W in the precoding matrix set satisfies the
following relationship: W=W.sub.1W.sub.2 or W=W.sub.2 W.sub.1,
where W.sub.1 is a first precoding submatrix, W.sub.2 is a second
precoding submatrix, indicates a Kronecker product, and a row
quantity of the first precoding submatrix is 2 and a row quantity
of the second precoding submatrix is 8, or a column quantity of the
first precoding submatrix is 8 and a column quantity of the second
precoding submatrix is 2.
[0099] In an embodiment, the UE determines the first precoding
submatrix and the second precoding submatrix from the precoding
matrix set. The UE determines the precoding matrix according to the
first precoding submatrix and the second precoding submatrix. It
should be understood that, the precoding matrix set herein may
further be an integration of multiple sets, or a precoding codebook
set meeting a condition is determined from a set.
[0100] In a 3D MIMO scenario, the determined precoding matrix W is
a Kronecker product of the first precoding matrix W.sub.1 and the
second precoding matrix W.sub.2:
W=W.sub.1W.sub.2.
[0101] According to a specific property of a Kronecker product, if
W.sub.1 is a matrix of m1 rows and m2 columns, and W.sub.2 is a
matrix of n1 rows and n2 columns, the finally determined matrix W
is a matrix of m1.times.n1 rows and m2.times.n2 columns. In a 3D
MIMO scenario with 16 antenna ports, a dimension of W should be 16,
so that the base station precodes a signal that needs to be
transmitted, and on the UE side, deprecoding is performed.
Therefore, a value of m1.times.n1 or m2.times.n2 should be 16. The
row quantity of the first precoding submatrix is 2, and the row
quantity of the second precoding submatrix is 8. Alternatively, the
column quantity of the first precoding submatrix is 8, and the
column quantity of the second precoding submatrix is 2. It should
be understood that, the present disclosure claims to protect all
types of variations of the case in which W=W.sub.1W.sub.2, for
example, cases in which W=W.sub.1.sup.TW.sub.2.sup.T or
W=W.sub.1W.sub.2.sup.T or W=W.sub.1W.sub.2. For the case in which
W=W.sub.1.sup.TW.sub.2.sup.T, as described above, dimensions of
columns of two matrices are respectively 2 and 8, or dimensions of
rows are respectively 2 and 8. One of dimensions of a finally
determined precoding matrix W should be 16. In this way, W or a
transpose of W may be used to perform precoding or deprecoding on a
signal. For the cases in which W=W.sub.1W.sub.2.sup.T and
W=W.sub.1.sup.TW.sub.2, the row quantity of the first precoding
submatrix may be 2 and the column quantity of the second precoding
submatrix may be 8; or the column quantity of the first precoding
submatrix may be 8 and the row quantity of the second precoding
submatrix may be 2. It should be understood that, the present
disclosure does not limit in such a manner that another operation
step is added after W is determined and before precoding or
decoding of precoding is performed on a matrix. For example,
vectors with a length of 16 are selected from W, to form another
matrix W', and then W' is used for deprecoding. It should be
understood that, formula variations that can represent ideas of the
present disclosure all fall within the protection scope of the
present disclosure.
[0102] It should be understood that, the precoding matrix set
should be a final selection range. That is, if a set {W}.sub.A
includes an element V that does not satisfy the relationship:
W=W.sub.1W.sub.2 or W=W.sub.2W.sub.1, but in a process of finally
determining a precoding matrix, V is excluded by using any other
condition, the precoding matrix set may not be a final element of
{W}.sub.A. Therefore, for a set {W}.sub.A including an element V,
if it is determined, through screening by using a condition, that
only one of a row quantity or a column quantity of {W}A is 8 or 2,
{W}A falls within the protection scope of the present disclosure.
For example, a set {W}.sub.B includes an element V.sub.1, and a row
quantity or a column quantity of V.sub.1 is neither 2 nor 8. If it
cannot be determined that V.sub.1 is either W.sub.1 or W.sub.2 in
any case, {W}.sub.B is not the precoding matrix, but {W}.sub.B' is
the precoding matrix. Any element in {W}.sub.B' may be determined,
by means of measurement, as W.sub.1 or W.sub.2. This also falls
within the protection scope of the present disclosure.
[0103] In still another embodiment, the first precoding submatrix
is a precoding submatrix in a first direction, and the second
precoding submatrix is a precoding submatrix in a second direction,
or the first precoding submatrix is a precoding submatrix in a
second direction and the second precoding submatrix is a precoding
submatrix in a first direction.
[0104] One precoding matrix may include two precoding submatrices.
For example, the two submatrices may be the first precoding
submatrix and the second precoding submatrix. In addition, the
precoding matrix may be formed in a manner of a product, or in a
manner corresponding to an antenna port precoding matrix model of
the precoding matrix, for example, in a form of a Kronecker
product. The precoding submatrix may have different physical
meanings. Sizes of codebooks having different dimensions may be
determined according to the physical meanings of the precoding
submatrix. For example, for 3D MIMO, each precoding matrix may
correspond to two arrangement directions of antenna ports, where
either direction may correspond to one precoding submatrix. In a
scenario with 16 antenna ports, antenna ports may be configured in
different manners according to different directions. In other
words, for different arrangement manners, each configuration manner
may be considered as a configuration. FIG. 2a, FIG. 2b, FIG. 2c,
and FIG. 2d show basic manners of configuring 16 antenna ports. In
FIG. 2a, two antenna ports are configured in the first direction
and eight antenna ports are configured in the second direction. In
FIG. 2b, four antenna ports are configured in the first direction
and four antenna ports are configured in the second direction. In
FIG. 2c, eight antenna ports are configured in the first direction
and two antenna ports are configured in the second direction. In
FIG. 2d, 16 antenna ports are configured in the first direction and
one antenna port is configured in the second direction.
[0105] That is, the 16 antenna ports are configured in any one of
the following manners:
[0106] two antenna ports are configured in the first direction and
eight antenna ports are configured in the second direction;
[0107] four antenna ports are configured in the first direction and
four antenna ports are configured in the second direction;
[0108] eight antenna ports are configured in the first direction
and two antenna ports are configured in the second direction;
or
[0109] 16 antenna ports are configured in the first direction and
one antenna port is configured in the second direction.
[0110] In the 3D MIMO scenario, the precoding matrix may be
determined by using a precoding matrix in the first direction and a
precoding matrix in the second direction. The precoding matrix in
the first direction corresponds to a first antenna port
configuration direction. The precoding matrix in the second
direction corresponds to a second antenna port configuration
direction. The first antenna port configuration direction and the
second antenna port configuration direction may be physically
actual configuration directions. Alternatively, in a dual-polarized
antenna port of 45.degree., an angle may be considered as one of a
vertical or horizontal configuration direction, and the other angle
is considered as the other one of the vertical or horizontal
configuration direction. The first precoding matrix and the second
precoding matrix may be separately precoding matrices in different
directions. For example, the precoding matrix in the first
direction corresponds to the first direction, and the precoding
matrix in the second direction corresponds to the second
direction.
[0111] Generally, there are four different antenna port
configurations for the 16 antenna ports. However, first precoding
matrices or second precoding matrices having a same dimension may
be determined for the four configurations according to an antenna
port configuration direction.
[0112] In an embodiment, a precoding matrix in the first direction
is a precoding matrix in a horizontal direction, and a precoding
matrix in the second direction is a precoding matrix in a vertical
direction, or a precoding matrix in the first direction is a
precoding matrix in a vertical direction, and a precoding matrix in
the second direction is a precoding matrix in a horizontal
direction. According to a division manner for the vertical
direction and the horizontal direction, more targeted selection may
be performed for the antenna port configuration according to user
distribution in an actual high-building scenario or a plain
scenario. For example, if there are relatively more users in the
vertical direction, more antenna ports in the vertical direction
may be configured.
[0113] In an embodiment, a matrix model W=W.sub.1W.sub.2 described
in the present disclosure may further be decomposed. That is, the
precoding matrix satisfies:
W=(W.sub.3.times.W.sub.4)W.sub.2.
[0114] W.sub.1=W.sub.3W.sub.4, where W.sub.3.times.W.sub.4 is a
matrix whose row quantity is 2 and W.sub.2 is a matrix whose row
quantity is 8, or W.sub.3.times.W.sub.4 is a matrix whose column
quantity is 2 and W.sub.2 is a matrix whose column quantity is 8.
Certainly, dimensions of W.sub.3.times.W.sub.4 and W.sub.2 herein
may further be exchanged. For example, W.sub.3.times.W.sub.4 is a
matrix whose row quantity is 8 and W.sub.2 is a matrix whose row
quantity is 2, or W.sub.3.times.W.sub.4 is a matrix whose column
quantity is 8 and W.sub.2 is a matrix whose column quantity is 2.
That is, the first precoding submatrix is a product of a third
precoding submatrix and a fourth precoding submatrix, and/or the
second precoding submatrix is a product of a fifth precoding
submatrix and a sixth precoding submatrix. W.sub.3 and W.sub.4 may
be two submatrices forming the precoding matrix in the first
direction, or W.sub.4 may be considered as a weighted matrix of
W.sub.3. A specific weighting manner may be the same of a non-3D
MIMO determining manner. For example, W.sub.3 may be used as a
long-term wideband-featured matrix, representing a long-term
wideband feature of the antenna port in the first direction.
W.sub.4 may be used as a short-term narrowband-featured matrix,
representing a short-term narrowband feature of the antenna port in
the first direction. It should be understood that, because one
dimension of the first precoding submatrix may be 2, and one
dimension of the second precoding submatrix may be 8, when a
dimension of W.sub.2 is either 8 or 2, a product of W.sub.3 and
W.sub.4 should have a dimension being the other one of 8 or 2. In
addition, the present disclosure claims to protect another
implementation manner similar to this, for example:
[0115] in a form that W=W.sub.1(W.sub.5.times.W.sub.6),
[0116] where W.sub.2=W.sub.5W.sub.6, or
[0117] in a form that W=(W.sub.3.times.W.sub.4)
(W.sub.5.times.W.sub.6), and
[0118] when at least one of the first precoding submatrix or the
second precoding submatrix may be indicated in a form of a product
of another two matrices, there may be more than two PMIs that need
to be fed back. For example, for a form that
W=(W.sub.3.times.W.sub.4) W.sub.2,
[0119] a PMI of W.sub.3, a PMI of W.sub.4, and a PMI of W.sub.2 may
be fed back. Some cases in such a form are shown by using examples
below: W.sub.2 is a matrix whose row quantity is 8, and a row
quantity of W.sub.3 is 2; or a column quantity of W.sub.2 is 8, and
a column quantity of W.sub.4 is 2; or W.sub.2 is a matrix whose row
quantity is 2, and a row quantity of W.sub.3 is 8; or a column
quantity of W.sub.2 is 2, and a column quantity of W.sub.4 is
8.
[0120] It should be understood that, such a form is also applicable
to W=W.sub.1(W.sub.5.times.W.sub.6): a row quantity of W.sub.1 is
8, and a row quantity of W.sub.5 is 2; or a column quantity of
W.sub.1 is 8, and a column quantity of W.sub.6 is 2; or a row
quantity of W.sub.1 is 2, and a row quantity of W.sub.5 is 8; or a
column quantity of W.sub.1 is 2, and a column quantity of W.sub.6
is 8.
[0121] Similarly, in a form that W=(W.sub.3.times.W.sub.4)
(W.sub.5.times.W.sub.6), a row quantity of W.sub.3 is 8, and a row
quantity of W.sub.5 is 2; or a column quantity of W.sub.4 is 8, and
a column quantity of W.sub.6 is 2; or a row quantity of W.sub.3 is
2, and a row quantity of W.sub.5 is 8; or a column quantity of
W.sub.4 is 2, and a column quantity of W.sub.6 is 8.
[0122] It should be understood that, in this embodiment of the
present disclosure, a first precoding matrix whose corresponding
dimension is 2 and a second precoding matrix whose dimension is 8
are determined from only one codebook set. Alternatively, there may
be two codebook sets, in one codebook set, dimensions are all 2,
and in the other codebook set, dimensions are all 8. Alternatively,
there are multiple codebook sets, and in the multiple codebook
sets, elements are all elements being 2 or 8, but it is finally
determined that the dimension of the first precoding matrix is 2
and the dimension of the second precoding matrix is 8. Considering
a special case, if matrices in a codebook set include codebooks of
other dimensions, these codebooks should not fall within a finally
determined range. Optionally, elements in one codebook set are put
together to obtain the first precoding matrix or the second
precoding matrix, but it is finally determined that dimensions of
the first precoding matrix and the second precoding matrix that
form the precoding matrix are respectively 2 and 8.
[0123] Step 204. The UE sends a precoding matrix indicator (PMI)
corresponding to the precoding matrix to the base station. The PMI
is used to indicate the precoding matrix.
[0124] It should be understood that, the present disclosure does
not limit a manner of feeding back the PMI. The PMI may be a field
in a piece of signaling, or may be a piece of signaling. In an
embodiment, in a case in which multiple precoding matrices need to
be indicated, there may be multiple PMIs. Alternatively, there may
be one PMI, but different parts of the PMI indicate different
precoding matrices. For example, in a PMI of eight bits, the first
three bits are used to indicate the PMI of the first precoding
matrix, and the last five bits are used to indicate the PMI of the
second precoding matrix. It should be understood that, in the
embodiments of the present disclosure, in terms of a PMI
corresponding to a matrix, the matrix may correspond to one field
of the PMI, or the matrix may correspond to a single PMI.
[0125] Optionally, the UE determines a bit quantity corresponding
to a PMI of W.sub.1 and a bit quantity corresponding to a PMI of
W.sub.2. The UE determines the PMI of W.sub.1 and the PMI of
W.sub.2 according to the bit quantity corresponding to the PMI of
W.sub.1 and the bit quantity corresponding to the PMI of W.sub.2.
The UE sends the PMI of W.sub.1 and the PMI of W.sub.2 to the base
station. In a case in which feedback resources of a PMI are fixed,
bits of the PMI are flexibly configured, so that a quantity of
elements in a precoding submatrix set can be increased.
[0126] In a 3D MIMO scenario with 16 antenna ports, antenna ports
can be extended in different directions because of different
configuration manners of the antenna ports. In this embodiment,
different antenna port counting manners are determined in different
configurations, so that in all the different configurations, a
matrix whose dimension is 8 and a matrix whose dimension is 2 are
determined in a precoding codebook, and a value of the PMI is fed
back to indicate a precoding matrix, thereby achieving an effect of
reducing configuration signaling and saving air interface
resources.
[0127] Because in this embodiment of the present disclosure, in a
case of 16 antenna ports, a precoding submatrix whose dimension is
8 and a precoding submatrix whose dimension is 2 in a codebook are
used, in addition to a counting effect that can be achieved in the
foregoing embodiments, a quantity of precoding submatrices in the
codebook can also be increased by using the saved resources,
thereby more accurately meeting an accuracy requirement of a
precoding matrix.
[0128] The following describes still another embodiment of the
present disclosure, where in a case in which feedback resources of
a PMI are fixed, bits of the PMI are flexibly configured, so that a
quantity of elements in a precoding submatrix set can be
increased.
[0129] FIG. 3 shows a PMI feedback method. It should be understood
that, this embodiment may be applied to other embodiments of the
present disclosure. For example, this embodiment may be used as a
more specific implementation manner of step 105 or step 205, or may
be implemented as a single embodiment.
[0130] Step 301. The UE determines a bit quantity corresponding to
a PMI of W.sub.1 and a bit quantity corresponding to a PMI of
W.sub.2.
[0131] In an embodiment, the determining process may be a process
of receiving signaling or an instruction, or a process of
determining according to a reference signal, or a process of
presetting, or a process of determining according to some other
properties.
[0132] Step 302. The UE determines the PMI of W.sub.1 and the PMI
of W.sub.2 according to the bit quantity corresponding to the PMI
of W.sub.1 and the bit quantity corresponding to the PMI of
W.sub.2.
[0133] Step 301 and step 302 may be performed according to the
following examples.
[0134] The UE determines bit quantities corresponding to PMIs in a
precoding matrix that need to be fed back. The UE determines,
according to the precoding matrix, the fed back PMIs.
[0135] For example, the codebook includes multiple precoding
submatrices, where a dimension of some precoding submatrices is 2,
and a dimension of some other precoding submatrices is 8. Some
submatrices whose dimension is 2 are used as an example.
TABLE-US-00001 Value (three bits) Value (two bits) of Corresponding
precoding matrix of PMI PMI (vector) 000 00 A1 001 -- A2 010 01 A3
011 -- A4 100 10 A5 101 -- A6 110 11 A7 111 -- A8
[0136] If there are eight matrices (A1 to A8) whose dimensions are
2 in a codebook set, when the UE determines that eight bits in a
precoding matrix can be used in total, and three bits of the eight
bits are used to indicate a matrix whose dimension is 2, it
indicates that sufficient bits are allocated to the UE, or the UE
determines that the UE has sufficient bits, to select, from the
eight codebooks A1 to A8, a precoding submatrix (where the
precoding submatrix may correspond to the first precoding submatrix
in the embodiments shown in FIG. 1 and FIG. 2) corresponding to the
measurement result. However, when the UE determines that eight bits
in the precoding matrix can be used in total, and only two bits of
the eight bits are used to indicate a matrix whose dimension is 2,
the UE can indicate only one of four candidate matrices. In this
case, feedback may be performed according to a preset rule, for
example, it is determined that 00, 01, 10, and 11 respectively
correspond to A1, A3, A5, and A7. In such a manner, accuracy is
affected, but air interface bit resources are saved. In some cases,
for example, when a precoding submatrix whose dimension is 2 does
not need an extremely accurate indication, but a precoding
submatrix whose dimension is 8 needs a relatively accurate
indication, a degree of accuracy of the precoding submatrix whose
dimension is 8 can be improved by reducing a quantity of bits
occupied by a PMI of the precoding submatrix whose dimension is 2.
Similarly, when a precoding submatrix whose dimension is 8 does not
need an extremely accurate indication, but a precoding submatrix
whose dimension is 2 needs a relatively accurate indication, a
degree of accuracy of the precoding submatrix whose dimension is 2
can be improved by reducing a quantity of bits occupied by a PMI of
the precoding submatrix whose dimension is 8. Currently, because
distribution of user equipments differs in different scenarios, for
example, in a high-building scenario, there are relatively more
users distributed in a vertical direction, in a process of
measuring and feeding back a PMI, if more precoding matrices that
are more accurate can be provided, a determined precoding matrix
can more accurately reflect a channel feature, thereby achieving an
objective of improving signal strength. Therefore, more bit values
need to be used to determine PMI feedback of the precoding
submatrix whose dimension is 2. In a scenario of a broad plain,
more dimension bit values need to be used to determine PMI feedback
of the precoding submatrix whose dimension is 8. It should be
understood that, an order of step 301 and step 302 may be reversed.
The UE may first determine PMIs that need to be fed back, and then
adjust accuracy after determining bit quantities of the fed back
PMIs. For example, it is determined that a PMI that needs to be fed
back is 001, but accuracy of a precoding submatrix in the direction
is lower than accuracy of a submatrix in another direction. It may
be determined, according to a preset rule, that 00 needs to be fed
back as a PMI in the direction, and A1 is used as a precoding
matrix in the direction, where A1 and A2 should relatively
approximately reflect channel features. In addition, the bit
quantity of the PMI of W.sub.1 and the bit quantity of the PMI
corresponding to W.sub.2 may be bit quantities of respective PMIs
of W.sub.1 and W.sub.2. If W.sub.1 and W.sub.2 are in different
fields of a same PMI, such bit quantity refers to a case of bit
allocation in the field to W.sub.1 and W.sub.2. When more than two
matrices need to be indicated by PMIs, for example, in another
embodiment, if it may be further determined that W.sub.1 is
represented by another two matrices, or it may be further
determined that W.sub.2 is represented by another two matrices, the
UE may determine quantities of bits occupied by PMIs corresponding
to multiple matrices.
[0137] It should be understood that, in the present disclosure, the
bit quantity being 8 and the corresponding table are merely an
example. The present disclosure further claims to protect feedback
of different bit quantities and a technical solution of adjustment
according to bit quantities that includes a form of a table and
another type, for example, a mapping type or a formula type of
precoding matrix determining manner.
[0138] Optionally, the determining, by the UE, bit quantities
corresponding to PMIs in a precoding matrix that need to be fed
back specifically includes: receiving a bit indication information
sent by a base station, where the bit indication information is
used to indicate the bit quantities corresponding to the PMIs that
need to be fed back; or
[0139] determining, by the UE according to the measurement, the bit
quantities corresponding to the PMIs that need to be fed back,
where in an embodiment, the UE sends, to the base station, the bit
quantities corresponding to the PMIs that need to be fed back, and
sending the bit quantities corresponding to the PMIs to the base
station.
[0140] Optionally, the UE may further receive a piece of scenario
information. The scenario information is used to indicate
configurations, in different directions, of the UE that correspond
to current communication between the UE and the base station.
Herein, the different directions may be the first direction and the
second direction, and may be specifically a horizontal direction
and a vertical direction respectively.
[0141] Step 303. Send the PMI of W.sub.1 and the PMI of W.sub.2 to
the base station.
[0142] According to the embodiment shown in FIG. 3, UE determines
the bit quantities corresponding to PMIs that need to be fed back,
and determines the fed back PMIs according to a precoding matrix
and the bit quantities corresponding to the PMIs. The technical
solution of this embodiment of the present disclosure can flexibly
adjust granularities of fed back bits of the PMIs, so that on same
feedback resources, a degree of beam accuracy in a direction is
flexibly set, thereby achieving an objective of meeting
requirements of various scenarios.
[0143] FIG. 4 is a schematic flowchart of a communication method
according to an embodiment of the present disclosure, and relates
to a precoding matrix indicator (PMI) feedback method. The method
specifically includes the following steps.
[0144] Step 401. A base station sends a reference signal to UE by
using 16 antenna ports.
[0145] Step 402. The base station receives a precoding matrix
indicator (PMI) fed back by the UE.
[0146] Step 403. The base station determines a precoding matrix
corresponding to the PMI from a precoding matrix set corresponding
to the 16 antenna ports, where each precoding matrix W in the
precoding matrix set satisfies the following relationship:
W=W.sub.1W.sub.2 or W=W.sub.2W.sub.1, wherein W.sub.1 is a first
precoding submatrix, W.sub.2 is a second precoding submatrix,
indicates a Kronecker product, and a row quantity of the first
precoding submatrix is 2 and a row quantity of the second precoding
submatrix is 8, or a column quantity of the first precoding
submatrix is 8 and a column quantity of the second precoding
submatrix is 2.
[0147] Step 404. The base station sends data to the UE by using the
precoding matrix.
[0148] According to the embodiment shown in FIG. 4, in a
configuration of 16 antenna ports, after performing measurement by
sending a reference signal, to obtain a measurement result, a base
station determines, from only one codebook set, a first precoding
matrix whose corresponding dimension is 2 and a second precoding
matrix whose dimension is 8, thereby reducing storage resources and
air interface configuration resources.
[0149] FIG. 5 is a schematic flowchart of a communication method
according to an embodiment of the present disclosure, and relates
to a precoding matrix indicator (PMI) feedback method. The method
specifically includes the following steps.
[0150] Step 501. A base station sends a reference signal to UE by
using 16 antenna ports.
[0151] In an embodiment, before step 501, the base station may
first determine to use the scenario with 16 antenna ports.
[0152] In another embodiment, the base station further indicates,
to the UE, that a quantity of the antenna ports is 16. For such an
indication process, indication may be directly performed by using a
piece of signaling, or indication to the UE may be performed in the
process of sending a reference signal in step 501, or indication
may be performed in the process of configuring the UE before step
501.
[0153] Step 502. The base station receives a precoding matrix
indicator (PMI) fed back by the UE.
[0154] It should be understood that, the present disclosure does
not limit a manner of feeding back the PMI. The PMI may be a field
in a piece of signaling, or may be a piece of signaling. In an
embodiment, if multiple precoding submatrices need to be indicated,
there may be multiple PMIs. Alternatively, there may be one PMI,
but different parts of the PMI indicate different precoding
submatrices. These precoding submatrices form the precoding matrix
according to a preset rule. The preset rule may be in a form of a
product or a Kronecker product. For example, in a PMI of eight
bits, the first three bits are used to indicate the PMI of the
first precoding matrix, and the last five bits are used to indicate
the PMI of the second precoding matrix. The first precoding matrix
and the second precoding matrix are both precoding submatrices. It
should be understood that, in the embodiments of the present
disclosure, in terms of a PMI corresponding to a matrix, the matrix
may correspond to one field of the PMI, or the matrix may
correspond to a single PMI.
[0155] Optionally, before the base station receives the precoding
matrix indicator (PMI) fed back by the UE, the base station
determines a bit quantity of a PMI of W.sub.1 and a bit quantity of
a PMI corresponding to W.sub.2. The base station receives,
according to the bit quantity of the PMI of W.sub.1 and the bit
quantity of the PMI corresponding to W.sub.2, at least two PMIs fed
back by the UE. This step may further be performed before the base
station sends the reference signal to the UE by using the 16
antenna ports.
[0156] If feedback resources of a PMI are fixed, bits of the PMI
are flexibly configured, so that a quantity of elements in a
precoding submatrix set can be increased.
[0157] Step 503. The base station determines a precoding matrix
corresponding to the PMI from a precoding matrix set corresponding
to the 16 antenna ports, where each precoding matrix W in the
precoding matrix set satisfies the following relationship:
W=W.sub.1W.sub.2 or W=W.sub.2W.sub.1, wherein W.sub.1 is a first
precoding submatrix, W.sub.2 is a second precoding submatrix,
indicates a Kronecker product, and a row quantity of the first
precoding submatrix is 2 and a row quantity of the second precoding
submatrix is 8, or a column quantity of the first precoding
submatrix is 8 and a column quantity of the second precoding
submatrix is 2.
[0158] Step 504. The base station sends data to the UE by using the
precoding matrix.
[0159] For example, a quantity of PMIs is at least two. The
determining, by the base station, a precoding matrix corresponding
to the at least two PMIs from a precoding matrix set corresponding
to the 16 antenna ports includes: determining, by the base station,
the first precoding submatrix and the second precoding submatrix
according to a PMI of the first precoding submatrix and a PMI of
the second precoding submatrix; and determining, by the base
station, the precoding matrix according to the first precoding
submatrix and the second precoding submatrix. It should be
understood that, the precoding matrix set herein may further be an
integration of multiple sets, or a precoding codebook set meeting a
condition is determined from a set.
[0160] In a 3D MIMO scenario, the determined precoding matrix W is
a Kronecker product of the first precoding matrix W.sub.1 and the
second precoding matrix W.sub.2:
W=W.sub.1W.sub.2.
[0161] According to a specific property of a Kronecker product, if
W.sub.1 is a matrix of m1 rows and m2 columns, and W.sub.2 is a
matrix of n1 rows and n2 columns, the finally determined matrix W
is a matrix of m1.times.n1 rows and m2.times.n2 columns. In a 3D
MIMO scenario with 16 antenna ports, a dimension of W should be 16,
so that the base station precodes a signal that needs to be
transmitted, and on the UE side, deprecoding is performed. In the
embodiments of the present disclosure, deprecoding herein may also
be referred to as decoding of precoding. Therefore, a value of
m1.times.n1 or m2.times.n2 should be 16. The row quantity of the
first precoding submatrix is 2, and the row quantity of the second
precoding submatrix is 8. Alternatively, the column quantity of the
first precoding submatrix is 8, and the column quantity of the
second precoding submatrix is 2. It should be understood that, the
present disclosure claims to protect all types of variations of the
case in which W=W.sub.1W.sub.2 or the case in which
W=W.sub.2W.sub.1, for example, cases in which
W=W.sub.1.sup.TW.sub.2.sup.T or W=W.sub.1W.sub.2.sup.T or
W=W.sub.1.sup.TW.sub.2. For the case in which
W=W.sub.1.sup.TW.sub.2.sup.T, as described above, dimensions of
columns of two matrices are respectively 2 and 8, or dimensions of
rows are respectively 2 and 8. One of dimensions of a finally
determined precoding matrix W should be 16. In this way, W or a
transpose of W may be used to perform precoding on a signal. For
the cases in which W=W.sub.1.sup.TW.sub.2.sup.T and
W=W.sub.1.sup.TW.sub.2, the row quantity of the first precoding
submatrix may be 2 and the column quantity of the second precoding
submatrix may be 8; or the column quantity of the first precoding
submatrix may be 8 and the row quantity of the second precoding
submatrix may be 2. It should be understood that, the present
disclosure does not limit in such a manner that another operation
step is added after W is determined and before precoding is
performed on a matrix. For example, vectors with a length of 16 are
selected from W, to form another matrix W', and then W' is used for
precoding. It should be understood that, formula variations that
can represent ideas of the present disclosure all fall within the
protection scope of the present disclosure.
[0162] It should be understood that, the precoding matrix set
should be a final selection range. That is, if a set {W}.sub.A
includes an element V that does not satisfy the relationship:
W=W.sub.1W.sub.2 or W=W.sub.2W.sub.1, but in a process of finally
determining a precoding matrix, V is excluded by using any other
condition, the precoding matrix set may not be a final element of
{W}.sub.A. Therefore, for a set {W}.sub.A including an element V,
if it is determined, through screening by using a condition, that
only one of a row quantity or a column quantity of {W}A is 8 or 2,
{W}.sub.A falls within the protection scope of the present
disclosure. For example, a set {W}.sub.B includes an element
V.sub.1, and a row quantity or a column quantity of V.sub.1 is
neither 2 nor 8. If it cannot be determined that V.sub.1 is either
W.sub.1 or W.sub.2 in any case, {W}.sub.B is not the precoding
matrix, but {W}.sub.B' is the precoding matrix. Any element in
{W}.sub.B' may be determined, by means of measurement, as W.sub.1
or W.sub.2. This also falls within the protection scope of the
present disclosure.
[0163] In still another embodiment, the first precoding submatrix
is a precoding submatrix in a first direction, and the second
precoding submatrix is a precoding submatrix in a second direction,
or the first precoding submatrix is a precoding submatrix in a
second direction and the second precoding submatrix is a precoding
submatrix in a first direction.
[0164] One precoding matrix may include two precoding submatrices.
For example, the two submatrices may be the first precoding
submatrix and the second precoding submatrix. In addition, the
precoding matrix may be formed in a manner of a product, or in a
manner corresponding to an antenna port precoding matrix model of
the precoding matrix, for example, in a form of a Kronecker
product. The precoding submatrix may have different physical
meanings. Sizes of codebooks having different dimensions may be
determined according to the physical meanings of the precoding
submatrix. For example, for 3D MIMO, each precoding matrix may
correspond to two arrangement directions of antenna ports, where
either direction may correspond to one precoding submatrix. In a
scenario with 16 antenna ports, antenna ports may be configured in
different manners according to different directions. In other
words, for different arrangement manners, each configuration manner
may be considered as a configuration. Refer to the basic manners of
configuring 16 antenna ports shown in FIG. 2a, FIG. 2b, FIG. 2c,
and FIG. 2d. Detailed descriptions have been provided in the
embodiment shown in FIG. 2, and the descriptions are not repeated
herein any further.
[0165] That is, the 16 antenna ports are configured in any one of
the following manners:
[0166] two antenna ports are configured in the first direction and
eight antenna ports are configured in the second direction;
[0167] four antenna ports are configured in the first direction and
four antenna ports are configured in the second direction;
[0168] eight antenna ports are configured in the first direction
and two antenna ports are configured in the second direction;
or
[0169] 16 antenna ports are configured in the first direction and
one antenna port is configured in the second direction.
[0170] In the 3D MIMO scenario, the precoding matrix may be
determined by using a precoding matrix in the first direction and a
precoding matrix in the second direction. The precoding matrix in
the first direction corresponds to a first antenna port
configuration direction. The precoding matrix in the second
direction corresponds to a second antenna port configuration
direction. The first antenna port configuration direction and the
second antenna port configuration direction may be physically
actual configuration directions. Alternatively, in a dual-polarized
antenna port of 45.degree., an angle may be considered as one of a
vertical or horizontal configuration direction, and the other angle
is considered as the other one of the vertical or horizontal
configuration direction. The first precoding matrix and the second
precoding matrix may be separately precoding matrices in different
directions. For example, the precoding matrix in the first
direction corresponds to the first direction, and the precoding
matrix in the second direction corresponds to the second
direction.
[0171] Generally, there are four different antenna port
configurations for the 16 antenna ports. However, first precoding
matrices or second precoding matrices having a same dimension may
be determined for the four configurations according to an antenna
port configuration direction.
[0172] In an embodiment, a precoding matrix in the first direction
is a precoding matrix in a horizontal direction, and a precoding
matrix in the second direction is a precoding matrix in a vertical
direction, or a precoding matrix in the first direction is a
precoding matrix in a vertical direction, and a precoding matrix in
the second direction is a precoding matrix in a horizontal
direction. According to a division manner for the vertical
direction and the horizontal direction, more targeted selection may
be performed for the antenna port configuration according to user
distribution in an actual high-building scenario or a plain
scenario. For example, if there are relatively more users in the
vertical direction, more antenna ports in the vertical direction
may be configured.
[0173] In an embodiment, a matrix model W=W.sub.1W.sub.2 described
in the present disclosure may further be decomposed. That is, the
precoding matrix satisfies:
W=(W.sub.3.times.W.sub.4)W.sub.2.
[0174] W.sub.1=W.sub.3W.sub.4, where W.sub.3.times.W.sub.4 is a
matrix whose row quantity is 2 and W.sub.2 is a matrix whose row
quantity is 8, or W.sub.3.times.W.sub.4 is a matrix whose column
quantity is 2 and W.sub.2 is a matrix whose column quantity is 8.
Certainly, dimensions of W.sub.3.times.W.sub.4 and W.sub.2 herein
may further be exchanged. For example, W.sub.3.times.W.sub.4 is a
matrix whose row quantity is 8 and W.sub.2 is a matrix whose row
quantity is 2, or W.sub.3.times.W.sub.4 is a matrix whose column
quantity is 8 and W.sub.2 is a matrix whose column quantity is 2.
That is, the first precoding submatrix is a product of a third
precoding submatrix and a fourth precoding submatrix, and/or the
second precoding submatrix is a product of a fifth precoding
submatrix and a sixth precoding submatrix. W.sub.3 and W.sub.4 may
be two submatrices forming the precoding matrix in the first
direction, or W.sub.4 may be considered as a weighted matrix of
W.sub.3. A specific weighting manner may be the same of a non-3D
MIMO determining manner. For example, W.sub.3 may be used as a
long-term wideband-featured matrix, representing a long-term
wideband feature of the antenna port in the first direction.
W.sub.4 may be used as a short-term narrowband-featured matrix,
representing a short-term narrowband feature of the antenna port in
the first direction. It should be understood that, because one
dimension of the first precoding submatrix may be 2, and one
dimension of the second precoding submatrix may be 8, when a
dimension of W.sub.2 is either 8 or 2, a product of W.sub.3 and
W.sub.4 should have a dimension being the other one of 8 or 2. In
addition, the present disclosure claims to protect another
implementation manner similar to this, for example:
[0175] in a form that W=W.sub.1(W.sub.5.times.W.sub.6),
[0176] where W.sub.2=W.sub.5W.sub.6, or
[0177] in a form that W=(W.sub.3.times.W.sub.4)
(W.sub.5.times.W.sub.6), and
[0178] when at least one of the first precoding submatrix or the
second precoding submatrix may be indicated in a form of a product
of another two matrices, there may be more than two PMIs that need
to be fed back. For example, for a form that
W=(W.sub.3.times.W.sub.4) W.sub.2,
[0179] a PMI of W.sub.3, a PMI of W.sub.4, and a PMI of W.sub.2
that are fed back by the UE may be received. Some cases in such a
form are shown by using examples below: W.sub.2 is a matrix whose
row quantity is 8, and a row quantity of W.sub.3 is 2; or a column
quantity of W.sub.2 is 8, and a column quantity of W.sub.4 is 2; or
W.sub.2 is a matrix whose row quantity is 2, and a row quantity of
W.sub.3 is 8; or a column quantity of W.sub.2 is 2, and a column
quantity of W.sub.4 is 8.
[0180] It should be understood that, such a form is also applicable
to W=W.sub.1(W.sub.5.times.W.sub.6): a row quantity of W.sub.1 is
8, and a row quantity of W.sub.5 is 2; or a column quantity of
W.sub.1 is 8, and a column quantity of W.sub.6 is 2; or a row
quantity of W.sub.1 is 2, and a row quantity of W.sub.5 is 8; or a
column quantity of W.sub.1 is 2, and a column quantity of W.sub.6
is 8.
[0181] Similarly, in a form that W=(W.sub.3.times.W.sub.4)
(W.sub.5.times.W.sub.6), a row quantity of W.sub.3 is 8, and a row
quantity of W.sub.5 is 2; or a column quantity of W.sub.4 is 8, and
a column quantity of W.sub.6 is 2; or a row quantity of W.sub.3 is
2, and a row quantity of W.sub.5 is 8; or a column quantity of
W.sub.4 is 2, and a column quantity of W.sub.6 is 8.
[0182] It should be understood that, in this embodiment of the
present disclosure, a first precoding matrix whose corresponding
dimension is 2 and a second precoding matrix whose dimension is 8
are determined from only one codebook set. Alternatively, there may
be two codebook sets, in one codebook set, dimensions are all 2,
and in the other codebook set, dimensions are all 8. Alternatively,
there are multiple codebook sets, and in the multiple codebook
sets, elements are all elements being 2 or 8, but it is finally
determined that the dimension of the first precoding matrix is 2
and the dimension of the second precoding matrix is 8. Considering
a special case, if matrices in a codebook set include codebooks of
other dimensions, these codebooks should not fall within a finally
determined range. Optionally, elements in one codebook set are put
together to obtain the first precoding matrix or the second
precoding matrix, but it is finally determined that dimensions of
the first precoding matrix and the second precoding matrix that
form the precoding matrix are respectively 2 and 8.
[0183] Because in this embodiment of the present disclosure, in a
case of 16 antenna ports, a precoding submatrix whose dimension is
8 and a precoding submatrix whose dimension is 2 in a codebook are
used, in addition to a counting effect that can be achieved in the
foregoing embodiments, a quantity of precoding submatrices in the
codebook can also be increased by using the reduced resources,
thereby more accurately meeting an accuracy requirement of a
precoding matrix.
[0184] The following describes still another embodiment of the
present disclosure, where if feedback resources of a PMI are fixed,
bits of the PMI are flexibly configured, so that a quantity of
elements in a precoding submatrix set can be increased.
[0185] FIG. 6 shows a precoding matrix determining method. It
should be understood that, this embodiment may be applied to other
embodiments of the present disclosure. For example, this embodiment
may be used as a more specific implementation manner of step 405 or
step 505, or may be implemented as a single embodiment.
[0186] Step 601. A base station determines a bit quantity
corresponding to a PMI of W.sub.1 and a bit quantity corresponding
to a PMI of W.sub.2.
[0187] In an embodiment, the determining process may be a process
of receiving signaling or an instruction of another network device,
for example, a network element of a core network, or another base
station, or a process of determining according to a channel
feature, or a process of presetting, or a process of determining
according to some other properties.
[0188] Step 602. The base station receives, according to the bit
quantity of the PMI corresponding to W.sub.1 and the bit quantity
of the PMI corresponding to W.sub.2, the PMI of W.sub.1 and the PMI
of W.sub.2 that are fed back by UE.
[0189] Step 601 and step 602 may be performed according to the
following examples.
[0190] The base station determines the bit quantity corresponding
to the PMI of W.sub.1 and the bit quantity corresponding to the PMI
of W.sub.2. The base station receives, according to the bit
quantity of the PMI of W.sub.1 and the bit quantity of the PMI
corresponding to W.sub.2, at least two PMIs fed back by the UE.
[0191] For example, the codebook includes multiple precoding
submatrices, where a dimension of some precoding submatrices is 2,
and a dimension of some other precoding submatrices is 8. Some
submatrices whose dimension is 2 are used as an example.
TABLE-US-00002 Value (three bits) Value (two bits) of Corresponding
precoding matrix of PMI PMI (vector) 000 00 A1 001 -- A2 010 01 A3
011 -- A4 100 10 A5 101 -- A6 110 11 A7 111 -- A8
[0192] If there are eight matrices (A1 to A8) whose dimensions are
2 in a codebook set, when the base station determines that eight
bits in a precoding matrix can be used in total, and three bits of
the eight bits are used to indicate a matrix whose dimension is 2,
it indicates that the base station allocates sufficient bits to the
UE, to select, from the eight codebooks A1 to A8, a precoding
submatrix (where the precoding submatrix may correspond to the
first precoding submatrix in the embodiments shown in FIG. 1 and
FIG. 2) corresponding to the measurement result. However, when the
base station determines that eight bits in the precoding matrix can
be used in total, and only two bits of the eight bits are used to
indicate a matrix whose dimension is 2, after the base station
notifies the UE, the UE can determine only one of four candidate
matrices. In this case, feedback may be performed according to a
preset rule, for example, it is determined that 00, 01, 10, and 11
respectively correspond to A1, A3, A5, and A7. In such a manner,
accuracy is affected, but air interface bit resources are reduced.
In some cases, for example, when a precoding submatrix whose
dimension is 2 does not need an extremely accurate indication, but
a precoding submatrix whose dimension is 8 needs a relatively
accurate indication, a degree of accuracy of the precoding
submatrix whose dimension is 8 can be improved by reducing a
quantity of bits occupied by a PMI of the precoding submatrix whose
dimension is 2. Similarly, when a precoding submatrix whose
dimension is 8 does not need an extremely accurate indication, but
a precoding submatrix whose dimension is 2 needs a relatively
accurate indication, a degree of accuracy of the precoding
submatrix whose dimension is 2 can be improved by reducing a
quantity of bits occupied by a PMI of the precoding submatrix whose
dimension is 8. Currently, because distribution of user equipments
differs in different scenarios, for example, in a high-building
scenario, there are relatively more users distributed in a vertical
direction, in a process of measuring and feeding back a PMI, if
more precoding matrices that are more accurate can be provided, a
determined precoding matrix can more accurately reflect a channel
feature, thereby achieving an objective of improving signal
strength. Therefore, more bit values need to be used to determine
PMI feedback of the precoding submatrix whose dimension is 2. In a
scenario of a broad plain, more dimension bit values need to be
used to determine PMI feedback of the precoding submatrix whose
dimension is 8. It should be understood that, generally, the base
station adjusts the bit quantity for the UE. However,
alternatively, the base station may receive a bit allocation
message of the UE, and the UE negotiates with the base station
about the bit quantity. In addition, the bit quantity of the PMI of
W.sub.1 and the bit quantity of the PMI corresponding to W.sub.2
may be bit quantities of respective PMIs of W.sub.1 and W.sub.2. If
W.sub.1 and W.sub.2 are in different fields of a same PMI, such bit
quantity refers to a case of bit allocation in the field to W.sub.1
and W.sub.2. When more than two matrices need to be indicated by
PMIs, for example, in another embodiment, if it may be further
determined that W.sub.1 is represented by another two matrices, or
it may be further determined that W.sub.2 is represented by another
two matrices, the base station may determine quantities of bits
occupied by PMIs corresponding to multiple matrices.
[0193] It should be understood that, in the present disclosure, the
bit quantity being 8 and the corresponding table are merely an
example. The present disclosure further claims to protect feedback
of different bit quantities and a technical solution of adjustment
according to bit quantities that includes a form of a table and
another type, for example, a mapping type or a formula type of
precoding matrix determining manner.
[0194] Optionally, the determining, by a base station, a bit
quantity corresponding to a PMI of W.sub.1 and a bit quantity
corresponding to a PMI of W.sub.2 specifically includes: receiving
a bit indication information, where the bit indication information
is used to indicate a bit quantity corresponding to a PMI that
needs to be fed back. The indication message may be from the UE or
another network device. Optionally, the base station determines the
bit quantity corresponding to the PMI of W.sub.1 and the bit
quantity corresponding to the PMI of W.sub.2.
[0195] Optionally, step 603: The base station sends bit indication
information to the UE, where the bit indication information is used
to indicate at least one of the bit quantity corresponding to the
PMI of W.sub.1 or the bit quantity corresponding to the PMI of
W.sub.2.
[0196] Optionally, the base station may further determine a piece
of scenario information. The scenario information is used to
indicate the bit quantities corresponding to the PMIs, which need
to be fed back by the base station, of W.sub.1 and W.sub.2
respectively, and configurations, in different directions, that
correspond to current communication between the UE and the base
station. Herein, the different directions may be the first
direction and the second direction, and may be specifically a
horizontal direction and a vertical direction respectively.
[0197] According to the embodiment shown in FIG. 6, a base station
determines a bit quantity corresponding to a PMI of W.sub.1 and a
bit quantity corresponding to a PMI of W.sub.2, and receives the
fed back PMIs. The technical solution of this embodiment of the
present disclosure can flexibly adjust granularities of fed back
bits of the PMIs, so that on same feedback resources, a degree of
beam accuracy in a direction is flexibly set, thereby achieving an
objective of meeting requirements of various scenarios.
[0198] FIG. 7 is a structural diagram of a communications apparatus
according to an embodiment of the present disclosure, and relates
to user equipment (UE). The apparatus specifically includes:
[0199] a receiving unit 701, configured to receive a reference
signal;
[0200] a determining unit 702, configured to: determine that a
quantity of antenna ports used by a base station to transmit the
reference signal is 16, and determine a precoding matrix from a
precoding matrix set corresponding to the 16 antenna ports, where
the reference signal is received by the receiving unit, and each
precoding matrix W in the precoding matrix set satisfies the
following relationship: W=W.sub.1W.sub.2 or W=W.sub.2W.sub.1, where
W.sub.1 is a first precoding submatrix, W.sub.2 is a second
precoding submatrix, indicates a Kronecker product, and a row
quantity of the first precoding submatrix is 2 and a row quantity
of the second precoding submatrix is 8, or a column quantity of the
first precoding submatrix is 8 and a column quantity of the second
precoding submatrix is 2; and
[0201] a sending unit 703, configured to send a precoding matrix
indicator (PMI) corresponding to the precoding matrix to the base
station, where the precoding matrix is determined by the
determining unit.
[0202] According to the embodiment shown in FIG. 7, in a
configuration of 16 antenna ports, after performing measurement
according to a reference signal to obtain a measurement result,
user equipment determines, from only one codebook set, a first
precoding matrix whose corresponding dimension is 2 and a second
precoding matrix whose dimension is 8, thereby reducing storage
resources and air interface configuration resources.
[0203] FIG. 8 is a schematic apparatus diagram of UE for
implementing PMI feedback according to an embodiment of the present
disclosure. The UE specifically includes the following units.
[0204] A receiving unit 801 is configured to receive a reference
signal.
[0205] A determining unit 802 is configured to: determine that a
quantity of antenna ports used by a base station to transmit the
reference signal is 16, and determine a precoding matrix from a
precoding matrix set corresponding to the 16 antenna ports, where
the reference signal is received by the receiving unit, and each
precoding matrix W in the precoding matrix set satisfies the
following relationship: or W=W.sub.1W.sub.2 or W=W.sub.2W.sub.1, is
where W.sub.1 is a first precoding submatrix, W.sub.2 is a second
precoding submatrix, indicates a Kronecker product, and a row
quantity of the first precoding submatrix is 2 and a row quantity
of the second precoding submatrix is 8, or a column quantity of the
first precoding submatrix is 8 and a column quantity of the second
precoding submatrix is 2.
[0206] It should be understood that, the present disclosure does
not limit a specific method for determining, by the determining
unit, that a quantity of antenna ports used by the base station to
transmit the reference signal is 16. The method may be
preconfigured by the UE, or may be determined by means of
measurement. In an embodiment, the determining unit may determine
the quantity of antenna ports according to the reference signal.
Such a determining process may be an implicit determining method.
For example, if the receiving unit receives only 16 reference
signals, the determining unit can determine the quantity of antenna
ports used by the base station to transmit the reference signal. In
another embodiment, the quantity of antenna ports used by the base
station to transmit the reference signal may not be determined by
the determining unit by using the reference signal, but is
configured by using some signaling, or has been prestored in the UE
by means of presetting or in another manner.
[0207] In an embodiment, the determining unit determines the first
precoding submatrix and the second precoding submatrix from the
precoding matrix set. The determining unit determines the precoding
matrix according to the first precoding submatrix and the second
precoding submatrix. It should be understood that, the precoding
matrix set herein may further be an integration of multiple sets,
or a precoding codebook set meeting a condition is determined from
a set.
[0208] In a 3D MIMO scenario, the determined precoding matrix W is
a Kronecker product of the first precoding matrix W.sub.1 and the
second precoding matrix W.sub.2:
W=W.sub.1W.sub.2.
[0209] According to a specific property of a Kronecker product, if
W.sub.1 is a matrix of m1 rows and m2 columns, and W.sub.2 is a
matrix of n1 rows and n2 columns, the finally determined matrix W
is a matrix of m1.times.n1 rows and m2.times.n2 columns. In a 3D
MIMO scenario with 16 antenna ports, a dimension of W should be 16,
so that the base station precodes a signal that needs to be
transmitted, and on the UE side, deprecoding is performed.
Therefore, a value of m1.times.n1 or m2.times.n2 should be 16. The
row quantity of the first precoding submatrix is 2, and the row
quantity of the second precoding submatrix is 8. Alternatively, the
column quantity of the first precoding submatrix is 8, and the
column quantity of the second precoding submatrix is 2. It should
be understood that, the present disclosure claims to protect all
types of variations of the case in which W=W.sub.1W.sub.2, for
example, cases in which W=W.sub.1.sup.TW.sub.2.sup.T or
W=W.sub.1W.sub.2.sup.T or W=W.sub.1.sup.TW.sub.2. For the case in
which W=W.sub.1.sup.TW.sub.2.sup.T, as described above, dimensions
of columns of two matrices are respectively 2 and 8, or dimensions
of rows are respectively 2 and 8. One of dimensions of a finally
determined precoding matrix W should be 16. In this way, W or a
transpose of W may be used to perform precoding or deprecoding on a
signal. For the cases in which W=W.sub.1W.sub.2.sup.T and
W=W.sub.1.sup.TW.sub.2, the row quantity of the first precoding
submatrix may be 2 and the column quantity of the second precoding
submatrix may be 8; or the column quantity of the first precoding
submatrix may be 8 and the row quantity of the second precoding
submatrix may be 2. It should be understood that, the present
disclosure does not limit in such a manner that another operation
step is added after W is determined and before precoding or
decoding of precoding is performed on a matrix. For example,
vectors with a length of 16 are selected from W, to form another
matrix W', and then W' is used for deprecoding. It should be
understood that, formula variations that can represent ideas of the
present disclosure all fall within the protection scope of the
present disclosure.
[0210] It should be understood that, the precoding matrix set
should be a final selection range. That is, if a set {W}.sub.A
includes an element V that does not satisfy the relationship:
W=W.sub.1W.sub.2 or W=W.sub.2W.sub.1, but in a process of finally
determining a precoding matrix, V is excluded by using any other
condition, the precoding matrix set may not be a final element of
{W}.sub.A. Therefore, for a set {W}.sub.A including an element V,
if it is determined, through screening by using a condition, that
only one of a row quantity or a column quantity of {W}.sub.A' is 8
or 2, {W}.sub.A falls within the protection scope of the present
disclosure. For example, a set {W}.sub.B includes an element
V.sub.1, and a row quantity or a column quantity of V.sub.1 is
neither 2 nor 8. If it cannot be determined that V.sub.1 is either
W.sub.1 or W.sub.2 in any case, {W}.sub.B is not the precoding
matrix, but {W}.sub.B' is the precoding matrix. Any element in
{W}.sub.B' may be determined, by means of measurement, as W.sub.1
or W.sub.2. This also falls within the protection scope of the
present disclosure.
[0211] In still another embodiment, the first precoding submatrix
is a precoding submatrix in a first direction, and the second
precoding submatrix is a precoding submatrix in a second direction,
or the first precoding submatrix is a precoding submatrix in a
second direction and the second precoding submatrix is a precoding
submatrix in a first direction.
[0212] One precoding matrix may include two precoding submatrices.
For example, the two submatrices may be the first precoding
submatrix and the second precoding submatrix. In addition, the
precoding matrix may be formed in a manner of a product, or in a
manner corresponding to an antenna port precoding matrix model of
the precoding matrix, for example, in a form of a Kronecker
product. The precoding submatrix may have different physical
meanings. Sizes of codebooks having different dimensions may be
determined according to the physical meanings of the precoding
submatrix. For example, for 3D MIMO, each precoding matrix may
correspond to two arrangement directions of antenna ports, where
either direction may correspond to one precoding submatrix. In a
scenario with 16 antenna ports, antenna ports may be configured in
different manners according to different directions. In other
words, for different arrangement manners, each configuration manner
may be considered as a configuration. FIG. 2a, FIG. 2b, FIG. 2c,
and FIG. 2d show basic manners of configuring 16 antenna ports.
[0213] That is, the 16 antenna ports are configured in any one of
the following manners:
[0214] two antenna ports are configured in the first direction and
eight antenna ports are configured in the second direction;
[0215] four antenna ports are configured in the first direction and
four antenna ports are configured in the second direction;
[0216] eight antenna ports are configured in the first direction
and two antenna ports are configured in the second direction;
or
[0217] 16 antenna ports are configured in the first direction and
one antenna port is configured in the second direction.
[0218] In the 3D MIMO scenario, the precoding matrix may be
determined by using a precoding matrix in the first direction and a
precoding matrix in the second direction. The precoding matrix in
the first direction corresponds to a first antenna port
configuration direction. The precoding matrix in the second
direction corresponds to a second antenna port configuration
direction. The first antenna port configuration direction and the
second antenna port configuration direction may be physically
actual configuration directions. Alternatively, in a dual-polarized
antenna port of 45.degree., an angle may be considered as one of a
vertical or horizontal configuration direction, and the other angle
is considered as the other one of the vertical or horizontal
configuration direction. The first precoding matrix and the second
precoding matrix may be separately precoding matrices in different
directions. For example, the precoding matrix in the first
direction corresponds to the first direction, and the precoding
matrix in the second direction corresponds to the second
direction.
[0219] Generally, there are four different antenna port
configurations for the 16 antenna ports. However, first precoding
matrices or second precoding matrices having a same dimension may
be determined for the four configurations according to an antenna
port configuration direction.
[0220] In an embodiment, a precoding matrix in the first direction
is a precoding matrix in a horizontal direction, and a precoding
matrix in the second direction is a precoding matrix in a vertical
direction, or a precoding matrix in the first direction is a
precoding matrix in a vertical direction, and a precoding matrix in
the second direction is a precoding matrix in a horizontal
direction. According to a division manner for the vertical
direction and the horizontal direction, more targeted selection may
be performed for the antenna port configuration according to user
distribution in an actual high-building scenario or a plain
scenario. For example, if there are relatively more users in the
vertical direction, more antenna ports in the vertical direction
may be configured.
[0221] In an embodiment, a matrix model W=W.sub.1W.sub.2 described
in the present disclosure may further be decomposed. That is, the
precoding matrix satisfies:
W=(W.sub.3.times.W.sub.4)W.sub.2.
[0222] W.sub.1=W.sub.3W.sub.4, where W.sub.3.times.W.sub.4 is a
matrix whose row quantity is 2 and W.sub.2 is a matrix whose row
quantity is 8, or W.sub.3.times.W.sub.4 is a matrix whose column
quantity is 2 and W.sub.2 is a matrix whose column quantity is 8.
Certainly, dimensions of W.sub.3.times.W.sub.4 and W.sub.2 herein
may further be exchanged. For example, W.sub.3.times.W.sub.4 is a
matrix whose row quantity is 8 and W.sub.2 is a matrix whose row
quantity is 2, or W.sub.3.times.W.sub.4 is a matrix whose column
quantity is 8 and W.sub.2 is a matrix whose column quantity is 2.
That is, the first precoding submatrix is a product of a third
precoding submatrix and a fourth precoding submatrix, and/or the
second precoding submatrix is a product of a fifth precoding
submatrix and a sixth precoding submatrix. W.sub.3 and W.sub.4 may
be two submatrices forming the precoding matrix in the first
direction, or W.sub.4 may be considered as a weighted matrix of
W.sub.3. A specific weighting manner may be the same of a non-3D
MIMO determining manner. For example, W.sub.3 may be used as a
long-term wideband-featured matrix, representing a long-term
wideband feature of the antenna port in the first direction.
W.sub.4 may be used as a short-term narrowband-featured matrix,
representing a short-term narrowband feature of the antenna port in
the first direction. It should be understood that, because one
dimension of the first precoding submatrix may be 2, and one
dimension of the second precoding submatrix may be 8, when a
dimension of W.sub.2 is either 8 or 2, a product of W.sub.3 and
W.sub.4 should have a dimension being the other one of 8 or 2. In
addition, the present disclosure claims to protect another
implementation manner similar to this, for example:
[0223] in a form that W=W.sub.1(W.sub.5.times.W.sub.6),
[0224] where W.sub.2=W.sub.5W.sub.6, or
[0225] in a form that
W=(W.sub.3.times.W.sub.4)(W.sub.5.times.W.sub.6), and
[0226] when at least one of the first precoding submatrix or the
second precoding submatrix may be indicated in a form of a product
of another two matrices, there may be more than two PMIs that need
to be fed back. For example, for a form that
W=(W.sub.3.times.W.sub.4)W.sub.2,
[0227] a PMI of W.sub.3, a PMI of W.sub.4, and a PMI of W.sub.2 may
be fed back. Some cases in such a form are shown by using examples
below: W.sub.2 is a matrix whose row quantity is 8, and a row
quantity of W.sub.3 is 2; or a column quantity of W.sub.2 is 8, and
a column quantity of W.sub.4 is 2; or W.sub.2 is a matrix whose row
quantity is 2, and a row quantity of W.sub.3 is 8; or a column
quantity of W.sub.2 is 2, and a column quantity of W.sub.4 is
8.
[0228] It should be understood that, such a form is also applicable
to W=W.sub.1(W.sub.5.times.W.sub.6): a row quantity of W.sub.1 is
8, and a row quantity of W.sub.5 is 2; or a column quantity of
W.sub.1 is 8, and a column quantity of W.sub.6 is 2; or a row
quantity of W.sub.1 is 2, and a row quantity of W.sub.5 is 8; or a
column quantity of W.sub.1 is 2, and a column quantity of W.sub.6
is 8.
[0229] Similarly, in a form that
W=(W.sub.3.times.W.sub.4)(W.sub.5.times.W.sub.6), a row quantity of
W.sub.3 is 8, and a row quantity of W.sub.5 is 2; or a column
quantity of W.sub.4 is 8, and a column quantity of W.sub.6 is 2; or
a row quantity of W.sub.3 is 2, and a row quantity of W.sub.5 is 8;
or a column quantity of W.sub.4 is 2, and a column quantity of
W.sub.6 is 8.
[0230] It should be understood that, in this embodiment of the
present disclosure, a first precoding matrix whose corresponding
dimension is 2 and a second precoding matrix whose dimension is 8
are determined from only one codebook set. Alternatively, there may
be two codebook sets, in one codebook set, dimensions are all 2,
and in the other codebook set, dimensions are all 8. Alternatively,
there are multiple codebook sets, and in the multiple codebook
sets, elements are all elements being 2 or 8, but it is finally
determined that the dimension of the first precoding matrix is 2
and the dimension of the second precoding matrix is 8. Considering
a special case, if matrices in a codebook set include codebooks of
other dimensions, these codebooks should not fall within a finally
determined range. Optionally, elements in one codebook set are put
together to obtain the first precoding matrix or the second
precoding matrix, but it is finally determined that dimensions of
the first precoding matrix and the second precoding matrix that
form the precoding matrix are respectively 2 and 8.
[0231] A sending unit 803 is configured to send a precoding matrix
indicator (PMI) corresponding to the precoding matrix to the base
station. The precoding matrix is determined by the determining
unit, and the PMI is used to indicate the precoding matrix.
[0232] It should be understood that, the present disclosure does
not limit a manner of feeding back the PMI. The PMI may be a field
in a piece of signaling, or may be a piece of signaling. In an
embodiment, if multiple precoding matrices need to be indicated,
there may be multiple PMIs. Alternatively, there may be one PMI,
but different parts of the PMI indicate different precoding
matrices. For example, in a PMI of eight bits, the first three bits
are used to indicate the PMI of the first precoding matrix, and the
last five bits are used to indicate the PMI of the second precoding
matrix. It should be understood that, in the embodiments of the
present disclosure, in terms of a PMI corresponding to a matrix,
the matrix may correspond to one field of the PMI, or the matrix
may correspond to a single PMI.
[0233] Optionally, the determining unit is further configured to
determine a bit quantity corresponding to a PMI of W.sub.1 and a
bit quantity corresponding to a PMI of W.sub.2. The UE determines
the PMI of W.sub.1 and the PMI of W.sub.2 according to the bit
quantity corresponding to the PMI of W.sub.1 and the bit quantity
corresponding to the PMI of W.sub.2. The sending unit sends the PMI
of W.sub.1 and the PMI of W.sub.2 to the base station. If feedback
resources of a PMI are fixed, bits of the PMI are flexibly
configured, so that a quantity of elements in a precoding submatrix
set can be increased.
[0234] In a 3D MIMO scenario with 16 antenna ports, antenna ports
can be extended in different directions because of different
configuration manners of the antenna ports. The UE device involved
in this embodiment determines different antenna port counting
manners in different configurations, so that in all the different
configurations, a matrix whose dimension is 8 and a matrix whose
dimension is 2 are determined in a precoding codebook, and a value
of the PMI is fed back to indicate a precoding matrix, thereby
reducing configuration signaling and reducing air interface
resources.
[0235] Because in this embodiment of the present disclosure, in a
case of 16 antenna ports, a precoding submatrix whose dimension is
8 and a precoding submatrix whose dimension is 2 in a codebook are
used, in addition to a counting effect that can be achieved in the
foregoing embodiments, a quantity of precoding submatrices in the
codebook can also be increased by using the reduced resources,
thereby more accurately meeting an accuracy requirement of a
precoding matrix.
[0236] The following describes still another embodiment of the
present disclosure, where if feedback resources of a PMI are fixed,
bits of the PMI are flexibly configured, so that a quantity of
elements in a precoding submatrix set can be increased.
[0237] In an embodiment, the determining unit is further configured
to: determine a bit quantity corresponding to a PMI of W.sub.1 and
a bit quantity corresponding to a PMI of W.sub.2, and determine the
PMI of W.sub.1 and the PMI of W.sub.2 according to the bit quantity
corresponding to the PMI of W.sub.1 and the bit quantity
corresponding to the PMI of W.sub.2.
[0238] In another embodiment, the determining unit is further
configured to control the receiving unit to receive bit indication
information sent by the base station. The bit indication
information is used to indicate at least one of the bit quantity
corresponding to the PMI of W.sub.1 or the bit quantity
corresponding to the PMI of W.sub.2.
[0239] FIG. 9 shows UE for implementing PMI feedback. It should be
understood that, this embodiment may be applied to other
embodiments of the present disclosure, or may be implemented as a
single embodiment.
[0240] A bit determining unit 901 is configured to determine a bit
quantity corresponding to a PMI of W.sub.1 and a bit quantity
corresponding to a PMI of W.sub.2. It should be understood that,
when being combined with the embodiment of FIG. 7 or FIG. 8, the
bit determining unit herein may be the determining unit in the
embodiments of FIG. 7 or FIG. 8.
[0241] In an embodiment, the determining process may be a process
of receiving signaling or an instruction, or a process of
determining according to a reference signal, or a process of
presetting, or a process of determining according to some other
properties.
[0242] The bit determining unit 901 is further configured to
determine the PMI of W.sub.1 and the PMI of W.sub.2 according to
the bit quantity corresponding to the PMI of W.sub.1 and the bit
quantity corresponding to the PMI of W.sub.2.
[0243] The bit determining unit 901 may perform an action according
to the following example.
[0244] The bit determining unit determines bit quantities
corresponding to PMIs in a precoding matrix that need to be fed
back. The bit determining unit determines, according to the
precoding matrix, the fed back PMIs.
[0245] For example, the codebook includes multiple precoding
submatrices, where a dimension of some precoding submatrices is 2,
and a dimension of some other precoding submatrices is 8. Some
submatrices whose dimension is 2 are used as an example.
TABLE-US-00003 Value (three bits) Value (two bits) of Corresponding
precoding matrix of PMI PMI (vector) 000 00 A1 001 -- A2 010 01 A3
011 -- A4 100 10 A5 101 -- A6 110 11 A7 111 -- A8
[0246] If there are eight matrices (A1 to A8) whose dimensions are
2 in a codebook set, when the UE determines that eight bits in a
precoding matrix can be used in total, and three bits of the eight
bits are used to indicate a matrix whose dimension is 2, it
indicates that sufficient bits are allocated to the UE, or the UE
determines that the UE has sufficient bits, to select, from the
eight codebooks A1 to A8, a precoding submatrix corresponding to
the measurement result, where the precoding submatrix may
correspond to the first precoding submatrix in the embodiments
shown in FIG. 1 and FIG. 2. Specifically, the determining may be
performed by the bit determining unit. However, when the bit
determining unit determines that eight bits in the precoding matrix
can be used in total, and only two bits of the eight bits are used
to indicate a matrix whose dimension is 2, the UE can indicate only
one of four candidate matrices. In this case, feedback may be
performed according to a preset rule, for example, it is determined
that 00, 01, 10, and 11 respectively correspond to A1, A3, A5, and
A7. In such a manner, accuracy is affected, but air interface bit
resources are reduced. In some cases, for example, when a precoding
submatrix whose dimension is 2 does not need an extremely accurate
indication, but a precoding submatrix whose dimension is 8 needs a
relatively accurate indication, a degree of accuracy of the
precoding submatrix whose dimension is 8 can be improved by
reducing a quantity of bits occupied by a PMI of the precoding
submatrix whose dimension is 2. Similarly, when a precoding
submatrix whose dimension is 8 does not need an extremely accurate
indication, but a precoding submatrix whose dimension is 2 needs a
relatively accurate indication, a degree of accuracy of the
precoding submatrix whose dimension is 2 can be improved by
reducing a quantity of bits occupied by a PMI of the precoding
submatrix whose dimension is 8. Currently, because distribution of
user equipments differs in different scenarios, for example, in a
high-building scenario, there are relatively more users distributed
in a vertical direction, in a process of measuring and feeding back
a PMI, if more precoding matrices that are more accurate can be
provided, a determined precoding matrix can more accurately reflect
a channel feature, thereby achieving an objective of improving
signal strength. Therefore, more bit values need to be used to
determine PMI feedback of the precoding submatrix whose dimension
is 2. In a scenario of a broad plain, more dimension bit values
need to be used to determine PMI feedback of the precoding
submatrix whose dimension is 8. It should be understood that, an
order of step 301 and step 302 may be reversed. The bit determining
unit may first determine PMIs that need to be fed back, and then
adjust accuracy after determining bit quantities of the fed back
PMIs. For example, it is determined that a PMI that needs to be fed
back is 001, but accuracy of a precoding submatrix in the direction
is lower than accuracy of a submatrix in another direction. It may
be determined, according to a preset rule, that 00 needs to be fed
back as a PMI in the direction, and A1 is used as a precoding
matrix in the direction, where A1 and A2 should relatively
approximately reflect channel features. In addition, the bit
quantity of the PMI of W.sub.1 and the bit quantity of the PMI
corresponding to W.sub.2 may be bit quantities of respective PMIs
of W.sub.1 and W.sub.2. If W.sub.1 and W.sub.2 are in different
fields of a same PMI, such bit quantity refers to a case of bit
allocation in the field to W.sub.1 and W.sub.2. When more than two
matrices need to be indicated by PMIs, for example, in another
embodiment, if it may be further determined that W.sub.1 is
represented by another two matrices, or it may be further
determined that W.sub.2 is represented by another two matrices, the
bit determining unit may determine quantities of bits occupied by
PMIs corresponding to multiple matrices.
[0247] It should be understood that, in the present disclosure, the
bit quantity being 8 and the corresponding table are merely an
example. The present disclosure further claims to protect feedback
of different bit quantities and a technical solution of adjustment
according to bit quantities that includes a form of a table and
another type, for example, a mapping type or a formula type of
precoding matrix determining manner.
[0248] Optionally, the determining, by the bit determining unit,
bit quantities corresponding to PMIs in a precoding matrix that
need to be fed back specifically includes: a bit receiving unit
902, configured to receive a bit indication information sent by a
base station, where the bit indication information is used to
indicate the bit quantities corresponding to the PMIs that need to
be fed back; or
[0249] determining, by the bit determining unit according to the
measurement, the bit quantities corresponding to the PMIs that need
to be fed back, where in an embodiment, a bit sending unit 903 is
configured to send, to the base station, the bit quantities
corresponding to the PMIs that need to be fed back, and sending the
bit quantities corresponding to the PMIs to the base station.
Similarly, when being combined with the embodiment of FIG. 7 or
FIG. 8, the bit receiving unit and the bit sending unit may be the
receiving unit and the sending unit respectively.
[0250] Optionally, the bit receiving unit may further receive a
piece of scenario information. The scenario information is used to
indicate configurations, in different directions, of the UE that
correspond to current communication between the UE and the base
station. Herein, the different directions may be the first
direction and the second direction, and may be specifically a
horizontal direction and a vertical direction respectively.
[0251] According to the embodiment shown in FIG. 9, the bit
determining unit determines the bit quantities corresponding to
PMIs that need to be fed back, and determines the fed back PMIs
according to a precoding matrix and the bit quantities
corresponding to the PMIs. The technical solution of this
embodiment of the present disclosure can flexibly adjust
granularities of fed back bits of the PMIs, so that on same
feedback resources, a degree of beam accuracy in a direction is
flexibly set, thereby achieving an objective of meeting
requirements of various scenarios.
[0252] FIG. 10 is a schematic apparatus diagram of base station for
implementing PMI feedback according to an embodiment of the present
disclosure. The apparatus specifically includes:
[0253] a sending unit 1001, configured to send a reference signal
to UE by using 16 antenna ports;
[0254] a receiving unit 1002, configured to receive a precoding
matrix indicator (PMI) fed back by the UE, where the PMI is
determined according to the reference signal sent by the sending
unit; and
[0255] a determining unit 1003, configured to determine a precoding
matrix corresponding to the PMI from a precoding matrix set
corresponding to the 16 antenna ports, where each precoding matrix
W in the precoding matrix set satisfies the following relationship:
W=W.sub.1W.sub.2 or W=W.sub.2W.sub.1, where W.sub.1 is a first
precoding submatrix, W.sub.2 is a second precoding submatrix,
indicates a Kronecker product, and a row quantity of the first
precoding submatrix is 2 and a row quantity of the second precoding
submatrix is 8, or a column quantity of the first precoding
submatrix is 8 and a column quantity of the second precoding
submatrix is 2, where
[0256] the sending unit is further configured to send data to the
UE by using the precoding matrix determined by the determining
unit.
[0257] According to the embodiment shown in FIG. 10, in a
configuration of 16 antenna ports, after the sending unit performs
measurement by sending a reference signal, to obtain a measurement
result, the determining unit determines, from only one codebook
set, a first precoding matrix whose corresponding dimension is 2
and a second precoding matrix whose dimension is 8, thereby
reducing storage resources and air interface configuration
resources.
[0258] FIG. 11 is a schematic apparatus diagram of base station for
implementing PMI feedback according to an embodiment of the present
disclosure. The base station specifically includes the following
units.
[0259] A sending unit 1101 is configured to send a reference signal
to UE by using 16 antenna ports.
[0260] In an embodiment, before the sending unit sends the
reference signal to the UE by using the 16 antenna ports, a
determining unit 1103 is further included, and is configured to
determine to use a scenario with the 16 antenna ports.
[0261] In another embodiment, the sending unit further indicates,
to the UE, that a quantity of the antenna ports is 16. For such an
indication process, indication may be directly performed by using a
piece of signaling, or indication to the UE may be performed in the
process of sending the reference signal by the sending unit, or
indication may be performed in the process of configuring the UE
before the reference signal is sent to the UE by using the 16
antenna ports.
[0262] A receiving unit 1102 is configured to receive a precoding
matrix indicator (PMI) fed back by the UE, where the PMI is
determined according to the reference signal sent by the sending
unit.
[0263] It should be understood that, the present disclosure does
not limit a manner of feeding back the PMI. The PMI may be a field
in a piece of signaling, or may be a piece of signaling. In an
embodiment, if multiple precoding submatrices need to be indicated,
there may be multiple PMIs. Alternatively, there may be one PMI,
but different parts of the PMI indicate different precoding
submatrices. These precoding submatrices form the precoding matrix
according to a preset rule. The preset rule may be in a form of a
product or a Kronecker product. For example, in a PMI of eight
bits, the first three bits are used to indicate the PMI of the
first precoding matrix, and the last five bits are used to indicate
the PMI of the second precoding matrix. The first precoding matrix
and the second precoding matrix are both precoding submatrices. It
should be understood that, in the embodiments of the present
disclosure, in terms of a PMI corresponding to a matrix, the matrix
may correspond to one field of the PMI, or the matrix may
correspond to a single PMI.
[0264] Optionally, before the receiving unit receives the precoding
matrix indicator (PMI) fed back by the UE, the determining unit is
configured to determine a bit quantity of a PMI of W.sub.1 and a
bit quantity of a PMI corresponding to W.sub.2. The receiving unit
receives, according to the bit quantity of the PMI of W.sub.1 and
the bit quantity of the PMI corresponding to W.sub.2, at least two
PMIs fed back by the UE. Therefore, if feedback resources of a PMI
are fixed, bits of the PMI are flexibly configured, so that a
quantity of elements in a precoding submatrix set can be
increased.
[0265] The determining unit is further configured to determine a
precoding matrix corresponding to the PMI from a precoding matrix
set corresponding to the 16 antenna ports, where each precoding
matrix W in the precoding matrix set satisfies the following
relationship: W=W.sub.1W.sub.2 or W=W.sub.2W.sub.1, where W.sub.1
is a first precoding submatrix, W.sub.2 is a second precoding
submatrix, indicates a Kronecker product, and a row quantity of the
first precoding submatrix is 2 and a row quantity of the second
precoding submatrix is 8, or a column quantity of the first
precoding submatrix is 8 and a column quantity of the second
precoding submatrix is 2.
[0266] The sending unit is further configured to send data to the
UE by using the precoding matrix determined by the determining
unit.
[0267] For example, a quantity of PMIs is at least two. The
determining, by the determining unit, a precoding matrix
corresponding to the at least two PMIs from a precoding matrix set
corresponding to the 16 antenna ports includes: determining, by the
determining unit, the first precoding submatrix and the second
precoding submatrix according to a PMI of the first precoding
submatrix and a PMI of the second precoding submatrix; and
determining, by the determining unit, the precoding matrix
according to the first precoding submatrix and the second precoding
submatrix. It should be understood that, the precoding matrix set
herein may further be an integration of multiple sets, or a
precoding codebook set meeting a condition is determined from a
set.
[0268] In a 3D MIMO scenario, the determined precoding matrix W is
a Kronecker product of the first precoding matrix W.sub.1 and the
second precoding matrix W.sub.2:
W=W.sub.1W.sub.2.
[0269] According to a specific property of a Kronecker product, if
W.sub.1 is a matrix of m1 rows and m2 columns, and W.sub.2 is a
matrix of n1 rows and n2 columns, the finally determined matrix W
is a matrix of m1.times.n1 rows and m2.times.n2 columns. In a 3D
MIMO scenario with 16 antenna ports, a dimension of W should be 16,
so that the base station precodes a signal that needs to be
transmitted, and on the UE side, deprecoding is performed.
Therefore, a value of m1.times.n1 or m2.times.n2 should be 16. The
row quantity of the first precoding submatrix is 2, and the row
quantity of the second precoding submatrix is 8. Alternatively, the
column quantity of the first precoding submatrix is 8, and the
column quantity of the second precoding submatrix is 2. It should
be understood that, the present disclosure claims to protect all
types of variations of the case in which W=W.sub.1W.sub.2 or the
case in which W=W.sub.2W.sub.1, for example, cases in which
W=W.sub.1.sup.TW.sub.2.sup.T or W=W.sub.1W.sub.2.sup.T or
W=W.sub.1.sup.TW.sub.2. For the case in which
W=W.sub.1.sup.TW.sub.2.sup.T, as described above, dimensions of
columns of two matrices are respectively 2 and 8, or dimensions of
rows are respectively 2 and 8. One of dimensions of a finally
determined precoding matrix W should be 16. In this way, W or a
transpose of W may be used to perform precoding on a signal. For
the cases in which W=W.sub.1W.sub.2.sup.T and
W=W.sub.1.sup.TW.sub.2, the row quantity of the first precoding
submatrix may be 2 and the column quantity of the second precoding
submatrix may be 8; or the column quantity of the first precoding
submatrix may be 8 and the row quantity of the second precoding
submatrix may be 2. It should be understood that, the present
disclosure does not limit in such a manner that another operation
step is added after W is determined and before precoding is
performed on a matrix. For example, vectors with a length of 16 are
selected from W, to form another matrix W', and then W' is used for
precoding. It should be understood that, formula variations that
can represent ideas of the present disclosure all fall within the
protection scope of the present disclosure.
[0270] It should be understood that, the precoding matrix set
should be a final selection range. That is, if a set {W}.sub.A
includes an element V that does not satisfy the relationship:
W=W.sub.1W.sub.2 or W=W.sub.2W.sub.1, but in a process of finally
determining a precoding matrix, V is excluded by using any other
condition, the precoding matrix set may not be a final element of
{W}A. Therefore, for a set {W}.sub.A including an element V, if it
is determined, through screening by using a condition, that only
one of a row quantity or a column quantity of {W}.sub.A' is 8 or 2,
{W}A falls within the protection scope of the present disclosure.
For example, a set {W}.sub.B includes an element V.sub.1, and a row
quantity or a column quantity of V.sub.1 is neither 2 nor 8. If it
cannot be determined that V.sub.1 is either W.sub.1 or W.sub.2 in
any case, {W}.sub.B is not the precoding matrix, but {W}.sub.B' is
the precoding matrix. Any element in {W}.sub.B' may be determined,
by means of measurement, as W.sub.1 or W.sub.2. This also falls
within the protection scope of the present disclosure.
[0271] In still another embodiment, the first precoding submatrix
is a precoding submatrix in a first direction, and the second
precoding submatrix is a precoding submatrix in a second direction,
or the first precoding submatrix is a precoding submatrix in a
second direction and the second precoding submatrix is a precoding
submatrix in a first direction.
[0272] One precoding matrix may include two precoding submatrices.
For example, the two submatrices may be the first precoding
submatrix and the second precoding submatrix. In addition, the
precoding matrix may be formed in a manner of a product, or in a
manner corresponding to an antenna port precoding matrix model of
the precoding matrix, for example, in a form of a Kronecker
product. The precoding submatrix may have different physical
meanings. The determining unit may determine, according to the
physical meanings of the precoding submatrix, sizes of codebooks
having different dimensions. For example, for 3D MIMO, each
precoding matrix may correspond to two arrangement directions of
antenna ports, where either direction may correspond to one
precoding submatrix. In a scenario with 16 antenna ports, antenna
ports may be configured in different manners according to different
directions. In other words, for different arrangement manners, each
configuration manner may be considered as a configuration. Refer to
the basic manners of configuring 16 antenna ports shown in FIG. 2a,
FIG. 2b, FIG. 2c, and FIG. 2d. Detailed descriptions have been
provided in the embodiment shown in FIG. 2, and the descriptions
are not repeated herein any further.
[0273] That is, the 16 antenna ports are configured in any one of
the following manners:
[0274] two antenna ports are configured in the first direction and
eight antenna ports are configured in the second direction;
[0275] four antenna ports are configured in the first direction and
four antenna ports are configured in the second direction;
[0276] eight antenna ports are configured in the first direction
and two antenna ports are configured in the second direction;
or
[0277] 16 antenna ports are configured in the first direction and
one antenna port is configured in the second direction.
[0278] In the 3D MIMO scenario, the precoding matrix may be
determined by using a precoding matrix in the first direction and a
precoding matrix in the second direction. The precoding matrix in
the first direction corresponds to a first antenna port
configuration direction. The precoding matrix in the second
direction corresponds to a second antenna port configuration
direction. The first antenna port configuration direction and the
second antenna port configuration direction may be physically
actual configuration directions. Alternatively, in a dual-polarized
antenna port of 45.degree., an angle may be considered as one of a
vertical or horizontal configuration direction, and the other angle
is considered as the other one of the vertical or horizontal
configuration direction. The first precoding matrix and the second
precoding matrix may be separately precoding matrices in different
directions. For example, the precoding matrix in the first
direction corresponds to the first direction, and the precoding
matrix in the second direction corresponds to the second
direction.
[0279] Generally, there are four different antenna port
configurations for the 16 antenna ports. However, first precoding
matrices or second precoding matrices having a same dimension may
be determined for the four configurations according to an antenna
port configuration direction.
[0280] In an embodiment, a precoding matrix in the first direction
is a precoding matrix in a horizontal direction, and a precoding
matrix in the second direction is a precoding matrix in a vertical
direction, or a precoding matrix in the first direction is a
precoding matrix in a vertical direction, and a precoding matrix in
the second direction is a precoding matrix in a horizontal
direction. According to a division manner for the vertical
direction and the horizontal direction, more targeted selection may
be performed for the antenna port configuration according to user
distribution in an actual high-building scenario or a plain
scenario. For example, if there are relatively more users in the
vertical direction, more antenna ports in the vertical direction
may be configured.
[0281] In an embodiment, a matrix model W=W.sub.1W.sub.2 described
in the present disclosure may further be decomposed. That is, the
precoding matrix satisfies:
W=(W.sub.3.times.W.sub.4)W.sub.2.
[0282] W.sub.1=W.sub.3W.sub.4, where W.sub.3.times.W.sub.4 is a
matrix whose row quantity is 2 and W.sub.2 is a matrix whose row
quantity is 8, or W.sub.3.times.W.sub.4 is a matrix whose column
quantity is 2 and W.sub.2 is a matrix whose column quantity is 8.
Certainly, dimensions of W.sub.3.times.W.sub.4 and W.sub.2 herein
may further be exchanged. For example, W.sub.3.times.W.sub.4 is a
matrix whose row quantity is 8 and W.sub.2 is a matrix whose row
quantity is 2, or W.sub.3.times.W.sub.4 is a matrix whose column
quantity is 8 and W.sub.2 is a matrix whose column quantity is 2.
That is, the first precoding submatrix is a product of a third
precoding submatrix and a fourth precoding submatrix, and/or the
second precoding submatrix is a product of a fifth precoding
submatrix and a sixth precoding submatrix. W.sub.3 and W.sub.4 may
be two submatrices forming the precoding matrix in the first
direction, or W.sub.4 may be considered as a weighted matrix of
W.sub.3. A specific weighting manner may be the same of a non-3D
MIMO determining manner. For example, W.sub.3 may be used as a
long-term wideband-featured matrix, representing a long-term
wideband feature of the antenna port in the first direction.
W.sub.4 may be used as a short-term narrowband-featured matrix,
representing a short-term narrowband feature of the antenna port in
the first direction. It should be understood that, because one
dimension of the first precoding submatrix may be 2, and one
dimension of the second precoding submatrix may be 8, when a
dimension of W.sub.2 is either 8 or 2, a product of W.sub.3 and
W.sub.4 should have a dimension being the other one of 8 or 2. In
addition, the present disclosure claims to protect another
implementation manner similar to this, for example:
[0283] in a form that W=W.sub.1(W.sub.5.times.W.sub.6),
[0284] where W.sub.2=W.sub.5W.sub.6, or
[0285] in a form that
W=(W.sub.3.times.W.sub.4)(W.sub.5.times.W.sub.6), and
[0286] when at least one of the first precoding submatrix or the
second precoding submatrix may be indicated in a form of a product
of another two matrices, there may be more than two PMIs that need
to be fed back. For example, for a form that
W=(W.sub.3.times.W.sub.4)W.sub.2,
[0287] the receiving unit receives a PMI of W.sub.3, a PMI of
W.sub.4, and a PMI of W.sub.2 that are fed back by the UE. Some
cases in such a form are shown by using examples below: W.sub.2 is
a matrix whose row quantity is 8, and a row quantity of W.sub.3 is
2; or a column quantity of W.sub.2 is 8, and a column quantity of
W.sub.4 is 2; or W.sub.2 is a matrix whose row quantity is 2, and a
row quantity of W.sub.3 is 8; or a column quantity of W.sub.2 is 2,
and a column quantity of W.sub.4 is 8.
[0288] It should be understood that, such a form is also applicable
to W=W.sub.1(W.sub.5.times.W.sub.6): a row quantity of W.sub.1 is
8, and a row quantity of W.sub.5 is 2; or a column quantity of
W.sub.1 is 8, and a column quantity of W.sub.6 is 2; or a row
quantity of W.sub.1 is 2, and a row quantity of W.sub.5 is 8; or a
column quantity of W.sub.1 is 2, and a column quantity of W.sub.6
is 8.
[0289] Similarly, in a form that
W=(W.sub.3.times.W.sub.4)(W.sub.5.times.W.sub.6), a row quantity of
W.sub.3 is 8, and a row quantity of W.sub.5 is 2; or a column
quantity of W.sub.4 is 8, and a column quantity of W.sub.6 is 2; or
a row quantity of W.sub.3 is 2, and a row quantity of W.sub.5 is 8;
or a column quantity of W.sub.4 is 2, and a column quantity of
W.sub.6 is 8.
[0290] It should be understood that, in this embodiment of the
present disclosure, a first precoding matrix whose corresponding
dimension is 2 and a second precoding matrix whose dimension is 8
are determined from only one codebook set. Alternatively, there may
be two codebook sets, in one codebook set, dimensions are all 2,
and in the other codebook set, dimensions are all 8. Alternatively,
there are multiple codebook sets, and in the multiple codebook
sets, elements are all elements being 2 or 8, but the dimension of
the first precoding matrix finally determined by the determining
unit is 2 and the dimension of the second precoding matrix finally
determined by the determining unit is 8. Considering a special
case, if matrices in a codebook set include codebooks of other
dimensions, these codebooks should not fall within a finally
determined range. Optionally, elements in one codebook set are put
together to obtain the first precoding matrix or the second
precoding matrix, but it is finally determined that dimensions of
the first precoding matrix and the second precoding matrix that
form the precoding matrix are respectively 2 and 8.
[0291] Because in this embodiment of the present disclosure, in a
case of 16 antenna ports, a precoding submatrix whose dimension is
8 and a precoding submatrix whose dimension is 2 in a codebook are
used, in addition to a counting effect that can be achieved in the
foregoing embodiments, a quantity of precoding submatrices in the
codebook can also be increased by using the reduced resources,
thereby more accurately meeting an accuracy requirement of a
precoding matrix.
[0292] The following describes still another embodiment of the
present disclosure, where if feedback resources of a PMI are fixed,
bits of the PMI are flexibly configured, so that a quantity of
elements in a precoding submatrix set can be increased.
[0293] In an embodiment, the determining unit is further configured
to determine a bit quantity of a PMI of W.sub.1 and a bit quantity
of a PMI corresponding to W.sub.2. The receiving unit is further
configured to receive, according to the bit quantity of the PMI
corresponding to W.sub.1 and the bit quantity of the PMI
corresponding to W.sub.2, the PMI of W.sub.1 and the PMI of W.sub.2
that are fed back by the UE.
[0294] Optionally, the determining unit is further configured to
control the sending unit to send bit indication information to the
UE, where the bit indication information is used to indicate at
least one of the bit quantity corresponding to the PMI of W.sub.1
or the bit quantity corresponding to the PMI of W.sub.2.
[0295] FIG. 12 shows a base station. It should be understood that,
this embodiment may be applied to other embodiments, for example,
FIG. 10 and FIG. 11, of the present disclosure, or may be
implemented as a single embodiment.
[0296] A bit determining unit 1201 is configured to determine a bit
quantity of a PMI of W.sub.1 and a bit quantity of a PMI
corresponding to W.sub.2.
[0297] In an embodiment, the determining process may be a process
of receiving signaling or an instruction of another network device,
for example, a network element of a core network, or another base
station, or a process of determining according to a channel
feature, or a process of presetting, or a process of determining
according to some other properties.
[0298] A bit receiving unit 1202 is configured to receive,
according to the bit quantity of the PMI corresponding to W.sub.1
and the bit quantity of the PMI corresponding to W.sub.2, the PMI
of W.sub.1 and the PMI of W.sub.2 that are fed back by UE.
[0299] It should be understood that, when this embodiment is
combined with FIG. 10 and FIG. 11, the bit determining unit may be
the determining unit, and the bit receiving unit may be the
receiving unit.
[0300] The bit determining unit determines the bit quantity
corresponding to the PMI of W.sub.1 and the bit quantity
corresponding to the PMI of W.sub.2. The bit receiving unit
receives, according to the bit quantity of the PMI of W.sub.1 and
the bit quantity the PMI corresponding to W.sub.2, at least two
PMIs fed back by the UE.
[0301] For example, the codebook includes multiple precoding
submatrices, where a dimension of some precoding submatrices is 2,
and a dimension of some other precoding submatrices is 8. Some
submatrices whose dimension is 2 are used as an example.
TABLE-US-00004 Value (three bits) Value (two bits) of Corresponding
precoding matrix of PMI PMI (vector) 000 00 A1 001 -- A2 010 01 A3
011 -- A4 100 10 A5 101 -- A6 110 11 A7 111 -- A8
[0302] If there are eight matrices (A1 to A8) whose dimensions are
2 in a codebook set, when the bit determining unit determines that
eight bits in a precoding matrix can be used in total, and three
bits of the eight bits are used to indicate a matrix whose
dimension is 2, it indicates that the base station allocates
sufficient bits to the UE, to select, from the eight codebooks A1
to A8, a precoding submatrix corresponding to the measurement
result. Such an allocation process may be performed by the bit
determining unit or an allocation unit. The precoding submatrix may
correspond to the first precoding submatrix in the embodiments
shown in FIG. 1 and FIG. 2. However, when the bit determining unit
determines that eight bits in the precoding matrix can be used in
total, and only two bits of the eight bits are used to indicate a
matrix whose dimension is 2, after the base station notifies the
UE, the UE can determine only one of four candidate matrices. In
this case, feedback may be performed according to a preset rule,
for example, it is determined that 00, 01, 10, and 11 respectively
correspond to A1, A3, A5, and A7. In such a manner, accuracy is
affected, but air interface bit resources are reduced. Herein, the
notification may be performed by a bit sending unit, but in
combination with FIG. 10 and FIG. 11, the notification may be
performed by the sending unit. In some cases, for example, when a
precoding submatrix whose dimension is 2 does not need an extremely
accurate indication, but a precoding submatrix whose dimension is 8
needs a relatively accurate indication, a degree of accuracy of the
precoding submatrix whose dimension is 8 can be improved by
reducing a quantity of bits occupied by a PMI of the precoding
submatrix whose dimension is 2. Similarly, when a precoding
submatrix whose dimension is 8 does not need an extremely accurate
indication, but a precoding submatrix whose dimension is 2 needs a
relatively accurate indication, a degree of accuracy of the
precoding submatrix whose dimension is 2 can be improved by
reducing a quantity of bits occupied by a PMI of the precoding
submatrix whose dimension is 8. Currently, because distribution of
user equipments differs in different scenarios, for example, in a
high-building scenario, there are relatively more users distributed
in a vertical direction, in a process of measuring and feeding back
a PMI, if more precoding matrices that are more accurate can be
provided, a determined precoding matrix can more accurately reflect
a channel feature, thereby achieving an objective of improving
signal strength. Therefore, more bit values need to be used to
determine PMI feedback of the precoding submatrix whose dimension
is 2. In a scenario of a broad plain, more dimension bit values
need to be used to determine PMI feedback of the precoding
submatrix whose dimension is 8. It should be understood that,
generally, the base station adjusts the bit quantity for the UE.
However, alternatively, the base station may receive a bit
allocation message of the UE, and the UE negotiates with the base
station about the bit quantity. In addition, the bit quantity of
the PMI of W.sub.1 and the bit quantity of the PMI corresponding to
W.sub.2 may be bit quantities of respective PMIs of W.sub.1 and
W.sub.2. If W.sub.1 and W.sub.2 are in different fields of a same
PMI, such bit quantity refers to a case of bit allocation in the
field to W.sub.1 and W.sub.2. When more than two matrices need to
be indicated by PMIs, for example, in another embodiment, if it may
be further determined that W.sub.1 is represented by another two
matrices, or it may be further determined that W.sub.2 is
represented by another two matrices, the bit determining unit may
determine quantities of bits occupied by PMIs corresponding to
multiple matrices.
[0303] It should be understood that, in the present disclosure, the
bit quantity being 8 and the corresponding table are merely an
example. The present disclosure further claims to protect feedback
of different bit quantities and a technical solution of adjustment
according to bit quantities that includes a form of a table and
another type, for example, a mapping type or a formula type of
precoding matrix determining manner.
[0304] Optionally, the determining, by a bit determining unit, a
bit quantity corresponding to a PMI of W.sub.1 and a bit quantity
corresponding to a PMI of W.sub.2 specifically includes: receiving,
by the bit receiving unit, a bit indication information, where the
bit indication information is used to indicate a bit quantity
corresponding to a PMI that needs to be fed back. The indication
message may be from the UE or another network device. Optionally,
the bit determining unit determines the bit quantity corresponding
to the PMI of W.sub.1 and the bit quantity corresponding to the PMI
of W.sub.2.
[0305] Optionally, the bit determining unit may further determine a
piece of scenario information. The scenario information is used to
indicate the bit quantities corresponding to the PMIs, which need
to be fed back by the base station, of W.sub.1 and W.sub.2
respectively, and configurations, in different directions, that
correspond to current communication between the UE and the base
station. Herein, the different directions may be the first
direction and the second direction, and may be specifically a
horizontal direction and a vertical direction respectively.
[0306] According to the embodiment shown in FIG. 12, a base station
determines a bit quantity corresponding to a PMI of W.sub.1 and a
bit quantity corresponding to a PMI of W.sub.2, and receives the
fed back PMIs. The technical solution of this embodiment of the
present disclosure can flexibly adjust granularities of fed back
bits of the PMIs, so that on same feedback resources, a degree of
beam accuracy in a direction is flexibly set, thereby achieving an
objective of meeting requirements of various scenarios.
[0307] The following provides a specific embodiment with reference
to the embodiments shown in FIG. 3, FIG. 6, FIG. 9, and FIG.
12.
[0308] FIG. 13 is a flowchart of a PMI feedback method according to
the present disclosure.
[0309] Step 1301. A base station determines a bit quantity
corresponding to a PMI of W.sub.1 and a bit quantity corresponding
to a PMI of W.sub.2. This step may be performed by a determining
unit of the base station.
[0310] Step 1302. The base station sends bit indication information
to UE, where the bit indication information is used to indicate at
least one of the bit quantity corresponding to the PMI of W.sub.1
or the bit quantity corresponding to the PMI of W.sub.2. This step
may be performed by a sending unit of the base station.
[0311] Step 1303. The UE receives the bit indication information
sent by the base station, where the bit indication information is
used to indicate at least one of the bit quantity corresponding to
the PMI of W.sub.1 or the bit quantity corresponding to the PMI of
W.sub.2. This step may be the receiving step performed by a
receiving unit of the UE.
[0312] In an embodiment, in step 1302, the base station may
determine a sending mode before sending the bit indication
information to the UE. The sending mode may be specifically
determined by using a signaling indication. Then a piece of bit
indication information is sent. Corresponding to different sending
modes, the bit indication information may indicate different PMIs
in different forms. The present disclosure provides the following
embodiments.
Embodiment 1
[0313] In the sending mode, a total quantity of bits occupied by a
PMI is determined. In this case, the bit indication information may
indicate one of the bit quantity of the PMI of W.sub.1 or the bit
quantity of the PMI of W.sub.2.
Embodiment 2
[0314] In the sending mode, a fixed bit quantity corresponding to
one of the bit quantity of the PMI of W.sub.1 or the bit quantity
of the PMI of W.sub.2 is determined. In this case, the bit
indication information may indicate the other one of the bit
quantity of the PMI of W.sub.1 or the bit quantity of the PMI of
W.sub.2.
[0315] Step 1304. The UE determines the bit quantity corresponding
to the PMI of W.sub.1 and the bit quantity corresponding to the PMI
of W.sub.2. This step may be the determining step performed by a
determining unit of the UE.
[0316] Step 1305. The UE determines the PMI of W.sub.1 and the PMI
of W.sub.2 according to the bit quantity corresponding to the PMI
of W.sub.1 and the bit quantity corresponding to the PMI of
W.sub.2. This step may be the sending step performed by the sending
unit of the UE.
[0317] Step 1306. The base station receives, according to the bit
quantity corresponding to the PMI of W.sub.1 and the bit quantity
corresponding to the PMI of W.sub.2, the PMI of W.sub.1 and the PMI
of W.sub.2 that are fed back by the UE. This step may be the
receiving step performed by a receiving unit of the base
station.
[0318] FIG. 14 shows still another system embodiment of the present
disclosure, and relates to a terminal apparatus and a base station.
The following steps are specifically included.
[0319] 1401. The base station sends a reference signal to the UE,
where a quantity of antenna ports used by the base station to send
the reference signal is eight.
[0320] 1402. The UE receives the reference signal.
[0321] 1403. The UE determines a value of a rank indicator.
[0322] 1404. Determine that the quantity of antenna ports is
eight.
[0323] 1405. The UE determines, according to the reference signal
and the rank indicator, a PMI corresponding to a precoding matrix
from a first codebook, where the first codebook is as follows:
TABLE-US-00005 TABLE 1 RI = 1 i.sub.2 i.sub.1 0 1 2 3 4 5 6 7 0-15
W.sub.2i.sub.1.sub., 0.sup.(1) W.sub.2i.sub.1.sub., 1.sup.(1)
W.sub.2i.sub.1.sub., 2.sup.(1) W.sub.2i.sub.1.sub., 3.sup.(1)
W.sub.2i.sub.1.sub.+1, .sub.0.sup.(1) W.sub.2i.sub.1.sub.+1,
1.sup.(1) W.sub.2i.sub.1.sub.+1, 2.sup.(1) W.sub.2i.sub.1.sub.+1,
3.sup.(1) i.sub.2 i.sub.1 8 9 10 11 12 13 14 15 0-15
W.sub.2i.sub.1.sub.+2, 0.sup.(1) W.sub.2i.sub.1.sub.+2, 1.sup.(1)
W.sub.2i.sub.1.sub.+2, 2.sup.(1) W.sub.2i.sub.1.sub.+2, 3.sup.(1)
W.sub.2i.sub.1.sub.+3, 0.sup.(1) W.sub.2i.sub.1.sub.+3, 1.sup.(1)
W.sub.2i.sub.1.sub.+3, 2.sup.(1) W.sub.2i.sub.1.sub.+3, 3.sup.(1)
where W m , n ( 1 ) = 1 8 [ v m .PHI. n v m ] ##EQU00001##
TABLE-US-00006 TABLE 2 RI = 2 i.sub.2 i.sub.1 0 1 2 3 0-15
W.sub.2i.sub.1.sub., 2i.sub.1.sub., 0.sup.(2) W.sub.2i.sub.1.sub.,
2i.sub.1.sub., 1.sup.(2) W.sub.2i.sub.1.sub.+1, 2i.sub.1.sub.+1,
0.sup.(2) W.sub.2i.sub.1.sub.+1, .sub.2i.sub.1.sub.+1,
.sub.1.sup.(2) i.sub.2 i.sub.1 4 5 6 7 0-15 W.sub.2i.sub.1.sub.+2,
2i.sub.1.sub.+2, 0.sup.(2) W.sub.2i.sub.1.sub.+2, 2i.sub.1.sub.+2,
1.sup.(2) W.sub.2i.sub.1.sub.+3, 2i.sub.1.sub.+3, 0.sup.(2)
W.sub.2i.sub.1.sub.+3, 2i.sub.1.sub.+3, 1.sup.(2) i.sub.2 i.sub.1 8
9 10 11 0-15 W.sub.2i.sub.1.sub., 2i.sub.1.sub.+1, 0.sup.(2)
W.sub.2i.sub.1.sub., 2i.sub.1.sub.+1, 1.sup.(2)
W.sub.2i.sub.1.sub.+1, 2i.sub.1.sub.+2, 0.sup.(2)
W.sub.2i.sub.1.sub.+1, 2i.sub.1.sub.+2, 1.sup.(2) i.sub.2 i.sub.1
12 13 14 15 0-15 W.sub.2i.sub.1.sub., 2i.sub.1.sub.+3, 0.sup.(2)
W.sub.2i.sub.1.sub., 2i.sub.1.sub.+3, 1.sup.(2)
W.sub.2i.sub.1.sub.+1, 2i.sub.1.sub.+3, 0.sup.(2)
W.sub.2i.sub.1.sub.+1, 2i.sub.1.sub.+3, 1.sup.(2) where W m , m ' ,
n ( 2 ) = 1 4 [ v m v m ' .PHI. n v m - .PHI. n v m ' ]
##EQU00002##
TABLE-US-00007 TABLE 3 RI = 3 i.sub.2 i.sub.1 0 1 2 3 0-3
W.sub.8i.sub.1.sub., 8i.sub.1.sub., 8i.sub.1.sub.+8.sup.(3)
W.sub.8i.sub.1.sub.+8, 8i.sub.1.sub., 8i.sub.1.sub.+8.sup.(3)
{tilde over (W)}.sub.8i.sub.1.sub., 8i.sub.1.sub.+8,
8i.sub.1.sub.+8.sup.(3) {tilde over (W)}.sub.8i.sub.1.sub.+8,
8i.sub.1.sub., 8i.sub.1.sup.(3) i.sub.2 i.sub.1 4 5 6 7 0-3
W.sub.8i.sub.1.sub.+2, 8i.sub.1.sub.+2, 8i.sub.1.sub.+10.sup.(3)
W.sub.8i.sub.1.sub.+10, 8i.sub.1.sub.+2, 8i.sub.1.sub.+10.sup.(3)
{tilde over (W)}.sub.8i.sub.1.sub.+2, 8i.sub.1.sub.+10,
8i.sub.1.sub.+10.sup.(3) {tilde over (W)}.sub.8i.sub.1.sub.+10,
8i.sub.1.sub.+2, 8i.sub.1.sub.+2.sup.(3) i.sub.2 i.sub.1 8 9 10 11
0-3 W.sub.8i.sub.1.sub.+4, 8i.sub.1.sub.+4,
8i.sub.1.sub.+12.sup.(3) W.sub.8i.sub.1.sub.+12, 8i.sub.1.sub.+4,
8i.sub.1.sub.+12.sup.(3) {tilde over (W)}.sub.8i.sub.1.sub.+4,
8i.sub.1.sub.+12, 8i.sub.1.sub.+12.sup.(3) {tilde over
(W)}.sub.8i.sub.1.sub.+12, 8i.sub.1.sub.+4, 8i.sub.1.sub.+4.sup.(3)
i.sub.2 i.sub.1 12 13 14 15 0-3 W.sub.8i.sub.1.sub.+6,
8i.sub.1.sub.+6, 8i.sub.1.sub.+14.sup.(3) W.sub.8i.sub.1.sub.+14,
8i.sub.1.sub.+6, 8i.sub.1.sub.+14.sup.(3) {tilde over
(W)}.sub.8i.sub.1.sub.+6, 8i.sub.1.sub.+14,
8i.sub.1.sub.+14.sup.(3) {tilde over (W)}.sub.8i.sub.1.sub.+14,
8i.sub.1.sub.+6, 8i.sub.1.sub.+6.sup.(3) where W m , m ' , m '' ( 3
) = 1 24 [ v m v m ' v m '' v m - v m ' - v m ' ] , W ~ m , m ' , m
'' ( 3 ) = 1 24 [ v m v m ' v m '' v m v m ' - v m '' ]
##EQU00003##
TABLE-US-00008 TABLE 4 RI = 4 i.sub.2 i.sub.1 0 1 2 3 0-3
W.sub.8i.sub.1.sub., 8i.sub.1.sub.+8, 0.sup.(4)
W.sub.8i.sub.1.sub., 8i.sub.1.sub.+8, 1.sup.(4)
W.sub.8i.sub.1.sub.+2, 8i.sub.1.sub.+10, 0.sup.(4)
W.sub.8i.sub.1.sub.+2, 8i.sub.1.sub.+10, 1.sup.(4) i.sub.2 i.sub.1
4 5 6 7 0-3 W.sub.8i.sub.1.sub.+4, 8i.sub.1.sub.+12, 0.sup.(4)
W.sub.8i.sub.1.sub.+4, 8i.sub.1.sub.+12, 1.sup.(4)
W.sub.8i.sub.1.sub.+6, 8i.sub.1.sub.+14, 0.sup.(4)
W.sub.8i.sub.1.sub.+6, 8i.sub.1.sub.+14, 1.sup.(4) where W m , m '
, n ( 4 ) = 1 32 [ v m v m ' v m v m ' .PHI. n v m .PHI. n v m ' -
.PHI. n v m - .PHI. n v m ' ] ##EQU00004##
TABLE-US-00009 TABLE 5 RI = 5 i.sub.2 i.sub.1 0 0-3 W i 1 ( 5 ) = 1
40 [ v 2 i 1 v 2 i 1 v 2 i 1 + 8 v 2 i 1 + 8 v 2 i 1 + 16 v 2 i 1 -
v 2 i 1 v 2 i 1 + 8 - v 2 i 1 + 8 v 2 i 1 + 16 ] ##EQU00005##
TABLE-US-00010 TABLE 6 RI = 6 i.sub.2 i.sub.1 0 0-3 W i 1 ( 6 ) = 1
48 [ v 2 i 1 v 2 i 1 v 2 i 1 + 8 v 2 i 1 + 8 v 2 i 1 + 16 v 2 i 1 +
16 v 2 i 1 - v 2 i 1 v 2 i 1 + 8 - v 2 i 1 + 8 v 2 i 1 + 16 - v 2 i
1 + 16 ] ##EQU00006##
TABLE-US-00011 TABLE 7 RI = 7 i.sub.2 i.sub.1 0 0-3 W i 1 ( 7 ) = 1
56 [ v 2 i 1 v 2 i 1 v 2 i 1 + 8 v 2 i 1 + 8 v 2 i 1 + 16 v 2 i 1 +
16 v 2 i 1 + 24 v 2 i 1 - v 2 i 1 v 2 i 1 + 8 - v 2 i 1 + 8 v 2 i 1
+ 16 - v 2 i 1 + 16 v 2 i 1 + 24 ] ##EQU00007##
TABLE-US-00012 TABLE 8 RI = 8 i.sub.2 i.sub.1 0 0 W i 1 ( 8 ) = 1 8
[ v 2 i 1 v 2 i 1 v 2 i 1 + 8 v 2 i 1 + 8 v 2 i 1 + 16 v 2 i 1 + 16
v 2 i 1 + 24 v 2 i 1 + 24 v 2 i 1 - v 2 i 1 v 2 i 1 + 8 - v 2 i 1 +
8 v 2 i 1 + 16 - v 2 i 1 + 16 v 2 i 1 + 24 - v 2 i 1 + 24 ]
##EQU00008##
[0324] A PMI 1 may be i1, a PMI 2 may be i2, Win the tables is each
codebook, .phi..sub.n=e.sup.j.pi.n/2, v.sub.m=v.sub.1v.sub.k,
v.sub.k=[1 e.sup.j2.pi.k/K].sup.T, v.sub.1=[1
e.sup.j2.pi.l/L].sup.T, and m, 1, and K satisfy: m=l.times.K+k,
k=mMOD K, and l=[m/K].
[0325] In an embodiment, a value of K is 8, and a value of L is
4.
[0326] 1406. The UE sends the PMI to the base station.
[0327] 1407. The base station receives a value of the PMI.
[0328] 1408. The base station determines the precoding matrix
according to the value of the PMI.
[0329] Optionally, the present disclosure does not limit logical
changes in orders of the steps, and combination, division, and
modification of the apparatuses.
[0330] It should be understood that, in the apparatus embodiments
of the present disclosure, apparatuses may be in various forms of
entity apparatuses. For example, in the apparatus embodiments of
the present disclosure, a sending unit may be a transmitter, or may
be an antenna or an antenna system. A receiving unit may be a
receiver, or may be an antenna or an antenna system. The
transmitter and the receiver may be a transceiver, or may be
combined into an antenna or an antenna system. The determining unit
may be one or more processors. A codebook, signaling, or a preset
rule, or other content that needs to be stored of the present
disclosure may be stored in a storage unit, which may be
specifically implemented in a form of a memory.
[0331] The processor may be a general-purpose processor, for
example, a general-purpose central processing unit (CPU), a network
processor (NP), or a micro-processor, or may be an
application-specific integrated circuit (ASIC), or one or more
integrated circuits for controlling execution of programs of
solutions of the present disclosure, or may be a digital signal
processor (DSP), an application-specific integrated circuit (ASIC),
a field programmable gate array (FPGA), or another programmable
logical device, discrete gate or transistor logical device, or
discrete hardware component. Alternatively, multiple processors may
implement different functions.
[0332] The memory stores a program for executing the technical
solutions of the present disclosure, and may further store an
operating system and another application program. Specifically, the
program may include program code, where the program code includes a
computer operation instruction. More specifically, the memory may
be a read-only memory (ROM), another type of static storage device
that can store static information and an instruction, a random
access memory (RAM), another type of dynamic storage device that
can store information and an instruction, a magnetic disk storage,
or the like. Alternatively, different memories may be used for
storage.
[0333] With descriptions of the foregoing embodiments, a person
skilled in the art may clearly understand that the present
disclosure may be implemented by hardware, firmware or a
combination thereof. When the present disclosure is implemented by
software, the foregoing functions may be stored in a
computer-readable medium or transmitted as one or more instructions
or code in the computer-readable medium. The computer-readable
medium includes a computer storage medium and a communications
medium, where the communications medium includes any medium that
enables a computer program to be transmitted from one place to
another. The storage medium may be any available medium accessible
to a computer. The following provides an example but does not
impose a limitation: The computer-readable medium may include a
RAM, a ROM, an EEPROM, a CD-ROM, or another optical disc storage or
disk storage medium, or another magnetic storage device, or any
other medium that can carry or store expected program code in a
form of an instruction or a data structure and can be accessed by a
computer. In addition, any connection may be appropriately defined
as a computer-readable medium. For example, if software is
transmitted from a website, a server or another remote source by
using a coaxial cable, an optical fiber/cable, a twisted pair, a
digital subscriber line (DSL) or wireless technologies such as
infrared ray, radio and microwave, the coaxial cable, optical
fiber/cable, twisted pair, DSL or wireless technologies such as
infrared ray, radio and microwave are included in fixation of a
medium to which they belong. For example, a disk and disc used by
the present disclosure includes a compact disc (CD), a laser disc,
an optical disc, a digital versatile disc (DVD), a floppy disk and
a Blu-ray disc, where the disk generally copies data by a magnetic
means, and the disc copies data optically by a laser means. The
foregoing combination should also be included in the protection
scope of the computer-readable medium.
[0334] In summary, what is described above is merely example
embodiments of the technical solutions of the present disclosure,
but is not intended to limit the protection scope of the present
disclosure. Any modification, equivalent replacement, or
improvement made without departing from the spirit and principle of
the present disclosure shall fall within the protection scope of
the present disclosure.
* * * * *